U.S. patent application number 10/961888 was filed with the patent office on 2006-04-13 for methods and uses of leptin in immune modulation.
Invention is credited to Eran Elinav, Yaron Ilan.
Application Number | 20060079443 10/961888 |
Document ID | / |
Family ID | 36146113 |
Filed Date | 2006-04-13 |
United States Patent
Application |
20060079443 |
Kind Code |
A1 |
Ilan; Yaron ; et
al. |
April 13, 2006 |
Methods and uses of leptin in immune modulation
Abstract
The present invention describes the use of leptin for the immune
modulation of the Th1/Th2 response. One aspect of the invention
provides for a shift in the Th1/Th2 cell balance towards
pro-inflammatory cytokine producing cells. This shift results from
an increase in the levels, expression and/or the activity of
leptin. Another aspect of the invention provides for a shift in the
Th1/Th2 cell balance towards anti-inflammatory cytokine producing
cells. This shift results from a decrease in the levels, expression
and/or the activity of leptin. The shifting of the Th1/Th2 balance
provides a method for the treatment of a variety of diseases and
disorders.
Inventors: |
Ilan; Yaron; (Givat Massua,
IL) ; Elinav; Eran; (Ramat Beit Hakerem, IL) |
Correspondence
Address: |
Natalie Bogdanos, Esq.;c/o Enzo Biochem, Inc.
9th Floor
527 Madison Avenue
New York
NY
10022
US
|
Family ID: |
36146113 |
Appl. No.: |
10/961888 |
Filed: |
October 8, 2004 |
Current U.S.
Class: |
514/5.8 ;
514/2.4; 514/3.3; 514/3.5; 514/3.7; 514/3.8; 514/4.6; 514/44A |
Current CPC
Class: |
A61K 38/2264
20130101 |
Class at
Publication: |
514/002 ;
514/044 |
International
Class: |
A61K 48/00 20060101
A61K048/00; A61K 38/17 20060101 A61K038/17 |
Claims
1. A method for immuno-modulation of the Th1/Th2 cell balance, in a
subject in need thereof, comprising the step of modulating the
levels, the expression and/or the activity of leptin in said
subject.
2. The method according to claim 1, wherein modulating the levels,
the expression and/or the activity of leptin is increasing or
decreasing the levels, the activity and/or the expression of leptin
in said subject.
3. The method according to any one of claims 1-2, wherein said
modulation of the Th1/Th2 cell balance is mediated by the
activation of immuno-regulatory cells selected from the group
consisting of NK T cells, antigen presenting cells and CD4.sup.+,
CD25.sup.+ T cells by leptin.
4. The method according to claim 3, for immuno-modulation resulted
by shifting of the Th1/Th2 cell balance toward the pro-inflammatory
cytokine producing cells, in a subject in need thereof, comprising
the step of increasing the levels, the expression and/or the
activity of leptin in said subject.
5. The method according to claim 4, wherein increasing the levels
or the expression of leptin in said subject is performed by
administering to said subject an immuno-modulatory effective amount
of leptin or any homologues, derivatives, functional fragments or
mixture thereof, an expression vector comprising nucleic acid
sequence encoding for leptin or any functional fragments thereof or
a composition comprising the same.
6. The method according to claim 5, wherein said subject is a
mammalian subject suffering of an immune-related disorder.
7. The method according to claim 6, wherein said immune-related
disorder is any one of a malignant proliferative disorder, a
disorder caused by immuno-suppression and an infection caused by a
pathogenic agent.
8. The method according to claim 7, wherein said malignant
proliferative disorder is any one of solid and non-solid tumor
selected from the group consisting of carcinoma, sarcoma, melanoma,
leukemia and lymphoma.
9. The method according to claim 8, wherein said carcinoma is
Hepatocellular carcinoma (HCC).
10. The method according to claim 7, wherein said
immuno-suppression is caused by infection of immunodeficiency
virus, preferably, HIV.
11. The method according to claim 7, wherein said infection is
caused by a pathogenic agent selected from the group consisting of
bacterial pathogens, viruses, fungi, parasites and yeast.
12. A method for the treatment of an immune-related disorder in a
subject in need thereof, comprising the step of administering to
said subject an immuno-modulatory effective amount of leptin or any
homologues, derivatives, functional fragments or mixture thereof,
an expression vector comprising nucleic acid sequence encoding for
leptin or any functional fragments thereof or a composition
comprising the same.
13. The method according to claim 12, wherein said effective amount
is an amount sufficient for shifting the Th1/Th2 cell balance
toward pro-inflammatory cytokine producing cells.
14. The method according to claim 13, wherein said immune-related
disorder is any one of a malignant proliferative disorder, a
disorder caused by immuno-suppression and an infection caused by a
pathogenic agent.
15. The method according to claim 14, wherein said malignant
proliferative disorder is any one of solid and non-solid tumor
selected from the group consisting of carcinoma, sarcoma, melanoma,
leukemia and lymphoma.
16. The method according to claim 15, wherein said carcinoma is
Hepatocellular carcinoma (HCC).
17. The method according to claim 14, wherein said
immuno-suppression is caused by infection of immunodeficiency
virus, preferably, HIV.
18. The method according to claim 14, wherein said infection is
caused by a pathogenic agent selected from the group consisting of
bacterial pathogens, viruses, fungi, parasites and yeast.
19. Use of leptin or any homologues, derivatives, functional
fragments or mixture thereof, an expression vector comprising
nucleic acid sequence encoding for leptin or any functional
fragments thereof for the preparation of a composition for shifting
the Th1/Th2 cell balance toward pro-inflammatory cytokine producing
cells.
20. Use of leptin or any homologues, derivatives, functional
fragments or mixture thereof, an expression vector comprising
nucleic acid sequence encoding for leptin or any functional
fragments thereof for the preparation of a medicament for the
treatment of an immune-related disorder.
21. The use according to claim 20, wherein said immune-related
disorder is any one of a malignant proliferative disorder, a
disorder caused by immuno-suppression and an infection caused by a
pathogenic agent.
22. The use according to claim 21, wherein said malignant
proliferative disorder is any one of solid and non-solid tumor
selected from the group consisting of carcinoma sarcoma, melanoma,
leukemia and lymphoma.
23. The use according to claim 2, wherein said carcinoma is
Hepatocellular carcinoma (HCC).
24. The method according to claim 21, wherein said
immuno-suppression is caused by infection of immunodeficiency
virus, preferably, HIV.
25. The method according to claim 21, wherein said infection is
caused by a pathogenic agent selected from the group consisting of
bacterial pathogens, viruses, fungi, parasites and yeast.
26. The method according to claim 3, for immuno-modulation resulted
by shifting the Th1/Th2 cell balance toward the anti-inflammatory
cytokine producing cells, in a subject in need thereof, comprising
the step of decreasing the levels, the expression and/or the
activity of leptin in said subject.
27. The method according to claim 26, wherein decreasing the
levels, the expression or the activity of leptin in said subject is
performed by administering to said subject an immuno-modulatory
effective amount of any one of an antibody specific for leptin and
a nucleic acid sequence capable of inhibiting the expression of
leptin selected from the group consisting of leptin anti-sense
nucleic acid sequence, a ribozyme, a small interfering RNA (siRNA)
specific for leptin and a composition comprising the same.
28. The method according to clam 27, wherein said subject is a
mammalian subject suffering of an immune-related disorder.
29. The method according to claim 28, wherein said immune-related
disorder is any one of an inflammatory disorder, an
autoimmune-disorder, a graft-rejection associated disorder and a
fibrotic disorder.
30. The method according to claim 29, wherein said inflammatory
disorder is an intestinal inflammatory disease.
31. The method according to claim 30, wherein said intestinal
inflammatory disease is inflammatory bowel diseases (IBD).
32. The method according to claim 29, wherein said fibrotic
disorder is any one of hepatic fibrosis, cardiac fibrosis and colon
fibrosis.
33. The method according to claim 29, wherein said auto-immune
disease is any one of arthritis, diabetes and immune related
infertility disorders.
34. A method for the treatment of an immune-related disorder in a
subject in need thereof, comprising the step of administering to
said subject an immuno-modulatory effective amount of any one of an
antibody specific for leptin and a nucleic acid sequence capable of
inhibiting the expression of leptin selected from the group
consisting of leptin anti-sense nucleic acid sequence, a ribozyme,
a small interfering RNA (siRNA) specific for leptin and a
composition comprising the same.
35. The method according to claim 34, wherein said effective amount
is an amount sufficient for shifting the Th1/Th2 cell balance
toward anti-inflammatory cytokine producing cells.
36. The method according to claim 35, wherein said immune-related
disorder is any one of an inflammatory disorder, an
autoimmune-disorder a graft-rejection associated disorder and a
fibrotic disorder.
37. The method according to claim 36, wherein said inflammatory
disorder is an intestinal inflammatory disease.
38. The method according to claim 37, wherein said intestinal
inflammatory disease is inflammatory bowel diseases (IBD).
39. The method according to claim 36, wherein said fibrotic
disorder is any one of hepatic fibrosis, cardiac fibrosis and colon
fibrosis.
40. The method according to claim 36, wherein said auto-immune
disease is any one of arthritis, diabetes and immune-related
infertility disorders.
41. Use of any one of an antibody specific for leptin and a nucleic
acid sequence capable of inhibiting the expression of leptin
selected from the group consisting of leptin anti-sense nucleic
acid sequence, a ribozyme and a small interfering RNA (siRNA)
specific for leptin for the preparation of a composition for
shifting the Th1/Th2 cell balance toward anti-inflammatory cytokine
producing cells.
42. Use of any one of an antibody specific for leptin and a nucleic
acid sequence capable of inhibiting the expression of leptin
selected from the group consisting of leptin anti-sense nucleic
acid sequence, a ribozyme, a small interfering RNA (siRNA) specific
for leptin for the preparation of a medicament for the treatment of
an immune-related disorder.
43. The use according to claim 42, wherein said immune-related
disorder is any one of an inflammatory disorder, an
autoimmune-disorder, a graft-rejection associated disorder and a
fibrotic disorder.
44. The method according to claim 43, wherein said inflammatory
disorder is an intestinal inflammatory disease.
45. The method according to claim 44, wherein said intestinal
inflammatory disease is inflammatory bowel diseases (IBD).
46. The method according to claim 43, wherein said fibrotic
disorder is any one of hepatic fibrosis, cardiac fibrosis and colon
fibrosis.
47. The method according to claim 43, wherein said auto-immune
disease is any one of arthritis, diabetes and immune-related
infertility disorders.
48. A method for the treatment of immune-related disorders in a
mammalian subject in need of such treatment, by manipulating NKT
cell population of said subject, wherein manipulation of said NK T
cell population results in modulation of the Th1/Th2 cell balance,
said method comprises the steps of: a. obtaining NK T cells from
said subject; b. ex vivo educating the NK T cells obtained in step
(a) such that the resulting educated NK T cells have the capability
of modulating the Th1/Th2 cell balance; and c. re-introducing to
said subject the educated NK T cells obtained in step (b) which are
capable of modulating the Th1/Th2 cell balance.
49. The method according to claim 48, wherein said ex vivo
education of step (b) is performed by culturing said NKT cells in
the presence of a. antigens associated with said immune-related
disorder or any combination thereof, b. an antigen presenting cell,
preferably, DC; and c. leptin or any homologues, derivatives,
functional fragments or mixture thereof, an expression vector
comprising nucleic acid sequence encoding for leptin or any
functional fragments thereof or a composition comprising the
same.
50. A therapeutic composition for the treatment of an
immune-related disorder in a mammalian subject, which composition
comprises as an effective ingredient ex vivo educated autologous NK
T cells capable of modulating the Th1/Th2 cell balance, and
optionally further comprising pharmaceutically acceptable carrier,
diluent, excipient and/or additive.
51. The composition according to claim 50, wherein said educated
autologous NKT cell is obtained by ex vivo culture in the presence
of: a. antigens associated with said immune-related disorder or any
combination thereof; b. an antigen presenting cell, preferably, DC;
and c. leptin or any homologues, derivatives, functional fragments
or mixture thereof, an expression vector comprising nucleic acid
sequence encoding for leptin or any functional fragments thereof or
a composition comprising the same.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to methods for modulation of
immune response. More particularly, the invention relates to
methods and uses of leptin for immuno-modulation of the balance
between Th1-Th2 responses and for the treatment of immune-related
disorders.
BACKGROUND OF THE INVENTION
[0002] The immune system plays a major part in tumor pathogenesis.
In animal models and in humans it has been demonstrated that tumor
cell formation leads to T cell activation aimed at tumor cell
destruction, while the development of cancer is related to specific
tumor-specific anergy. Conditions of immunodeficiency, such as
infection with HIV and prolonged immunosuppressive therapy are
associated with an increased incidence of cancer formation. Several
experimental and clinical immunomodulatory strategies are employed
to activate a pro-inflammatory immune response in systemically
disseminated tumors. Examples are numerous and include IL2 and
IFN-.alpha. treatment in metastatic melanoma [Eigentler, T. K. et
al., Lancet Oncol. 4(12):748-59 (2003)], IFN treatment in
metastatic renal cell carcinoma [Gitlitz, B. J. and Figlin, R. A.
Urol. Clin. North. Am. 30(3):589-600 (2003)], TNF-.alpha. therapy
in metastatic thyroid carcinoma [Mitsiades, C. S. et al.
Endocrinol. 178(2):205-16 (2003)], the use of
granulocyte-colony-stimulating-factor (GCSF) as a dendritic cell
activator in breast, prostate, and renal cancer [Waller, E. K. and
Ernstoff, M. S. Cancer 1; 97(7):1797-809 (2003)], and transfer of
alloreactive donor T lymphocytes to promote the `graft versus
leukemia` effect in hematological malignancies [Costello, R. T., et
al., Eur. J. Haematol. 70(5):333-45 (2003)].
[0003] Leptin is an 18 kDa product of the ob gene that was
discovered in 1994 [Zhang, Y. et al., Nature 372:425-432 (1994)].
This protein is secreted almost exclusively by adipose cells, and
acts centrally at the hypothalamic region in regulating energy
expenditure and appetite [Pelleymounter, M. A. et al., Science
269:540-543 (1995)]. Leptin deficient ob/ob mice suffer of morbid
obesity, diabetes mellitus, hyperlipidemia and hepatic steatosis,
while leptin administration to these mice results in reversal of
these disorders [Halaas, J. L. et al., Science 269:543-546 (1995)].
In contrast, the administration of leptin to humans suffering from
morbid obesity failed to suppress appetite or reduce weight
[Friedman, J. M. et al., Nutr. Rev. 60(10 Pt 2):S1-14; discussion
S68-84, 85-7 (2002)]. This disappointing result may stem from
increased leptin levels in obese individuals, and `leptin
resistance` caused by other, newly discovered, regulatory proteins
such as adiponectin [Mark, A. L. et al., J. Hypertens.
20(7):1245-50 (2002); Berg, A. H. et al., Trends Endocrinol. Metab.
13(2):84-9 (2002)].
[0004] It has been previously suggested that leptin possesses
potent immunomodulatory properties [Loffreda, S. et al.,
12(1):57-65 (1998)]. Structurally, leptin is similar to IL2, IL6,
and IL15, making it a member of the helical cytokine superfamily
[Madej, T. et al., FEBS Lett. 2;373(1):13-8 (1995)], while leptin
receptors are structurally similar to hematopoietic cytokine
receptors [Gimble, J. M. et al., Bone 19(5):421-8 (1996)]. Leptin
receptors are found on CD4 and CD8 lymphocytes, monocytes
[Sanchez-Margalet, V. Clin. Exp. Immunol. 129(1):119-24 (2002)],
natural-killer lymphocytes [Zhao, Y. et al., Biochem. Biophys. Res.
Commun. 10:300(2):247-52 (2003); Motivala, S. J. et al., Alcohol.
Clin. Exp. Res. 27(11):1819-24 (2003)], and hepatic stellate cells
[Saxena, N. K. et al., Hepatology 35(4):762-71 (2002)]. Leptin
enhances T cell proliferation and pro-inflammatory cytokine
secretion [Lord, G. M. et al., Nature 27;394(6696):897-901 (1998);
Lord, G. M. et al., J. Leukoc. Biol. 72(2):330-8 (2002);
Martin-Romero, C. et al., Cell. Immunol. 10;199(1):15-24 (2000)],
by activating the JAK/STAT signal trasnduction pathway [Cao, Q. et
al., J. Biol. Chem. 6;279(6):4292-304 (2004)]. Leptin deficient
ob/ob mice are immune deficient, suffering from an increased
propensity for infection and mortality [Faggioni, R. et al., FASEB
J. 15(14):2565-71 (2001)] and impaired function of NKT lymphocytes
and hepatic macrophages [Li, Z. et al., Gastroenterology
123(4):1304-10 (2002)]. These mice are resistant to several Th1
mediated immune disorders, including allergic experimental
encephalomyelitis [Matarese, G. et al., J. Immunol.
15;166(10):5909-16 (2001)], concanavalin A hepatitis [Siegmund, B.
et al., Eur. J. Immunol. 32(2):552-60 (2002)], experimental
arthritis [Busso, N. et al., J. Immunol. 15;168(2):875-82 (2002)],
and autoimmune nephritis [Tarzi, R. M. et al., Am. J. Pathol.
164(2):385-90 (2004)] but are extremely vulnerable to LPS-induced
hepatic damage [Yang, S. et al., Am. J. Physiol. Gastrointest.
Liver Physiol. 281(2):G382-92 (2001)]. Leptin replenishment
reverses all of these disorders.
[0005] Wildtype mice that do not suffer from leptin deficiency
develop a potentiation in severity of experimental allergic
encephalomyelitis [Matarese, G. et al., Eur. J. Immunol.
31(5):1324-32 (2001)] and type I diabetes mellitus [Matarese, G. et
al. Diabetes 51(5):1356-61 (2002)]. In humans, no trials have
examined the relationship between leptin and immune phenomena.
However, the elevated leptin levels among females (that also suffer
from an unexplained increased tendency for the development of
autoimmune disease) and the reduced levels of leptin among
malnourished individuals (that also tend to develop secondary
immune deficiency) may point out to leptin being a link between
nutrition and immunity [Matarese, g. et al., Trends in immunology.
23(4):182-7 (2002)].
[0006] Aberrant leptin receptors have been found on breast [Hu, X.
et al., J. Natl. Cancer. Inst. 20;94(22):1704-11 (2002)],
endometrial [Yuan, S. S. et al., Gynecol. Oncol. 92(3):769-75
(2004)], bladder [Yuan, S. S. et al., Urology. 63(2):408-13
(2004)], and esophageal [Somasundar, P. et al., Am. J. Surg.
186(5):575-8 (2003)] cancer cell lines. Leptin has been recently
demonstrated to activate proliferation of breast [Catalano, S. et
al., J. Biol. Chem. 25 (2004)], prostate [Onuma, M. et al., J.
Biol. Chem. 24:278(43):42660-7 (2003)], pancreas [Somasundar, P. et
al., J. Surg. Res. 113(1):50-5 (2003)], and colon [Rouet-Benzineb,
P. et al., J. Biol. Chem. 29 (2004)] cancer cell lines through
direct activation of JAK/STAT signal transduction pathway. Thus,
leptin may exert two opposing effects--a direct, pro-proliferative
effect on tumor cells and an indirect, pro-inflammatory and
anti-tumoral immune response. The net balance between these two
leptin-induced reactions may determine whether it may play a pro or
anti tumorogenic effect.
[0007] The present invention shows a clear involvement of leptin in
modulation of Th1 immune response, and pro-inflammatory cytokine
secretion, particularly through NKT lymphocyte activation. Such
modulation enables the use of leptin as an immunomodulator for the
treatment of different immune-related disorders, particularly,
disorders involving NK cells.
[0008] It is therefore an object of the invention to provide a
method for the modulation of Th1-Th2 response, and more
particularly to enhance a pro-inflammatory cytokine secretion.
[0009] Another object of the invention is to provide method for the
treatment immune-related disorders by modulating the expression of
leptin.
[0010] The invention further provides for the use of leptin in the
treatment of immune-related disorders and in immuno-modulation.
[0011] These and other objects of the invention will become
apparent as the description proceeds.
SUMMARY OF THE INVENTION
[0012] In a first aspect, the present invention relates to a method
for immuno-modulation of the Th1/Th2 cell balance, in a subject in
need thereof, comprising the step of modulating the levels, the
expression and/or the activity of leptin in said subject.
[0013] According to one embodiment, modulation of the Th1/Th2 cell
balance by the method of the invention may be performed by
increasing or decreasing the levels, the activity and/or the
expression of leptin in said subject.
[0014] According to another preferred embodiment, modulation of the
Th1/Th2 cell balance may be mediated by the activation of
immuno-regulatory cells selected from the group consisting of NK T
cells, antigen presenting cells and CD4.sup.+, CD25.sup.+ T cells,
and preferably, NK T cells, by leptin.
[0015] In one specific embodiment, the invention provides for a
method for immuno-modulation resulted by shifting of the Th1/Th2
cell balance toward the pro-inflammatory cytokine producing cells,
in a subject in need thereof. Accordingly, this method comprises
the step of increasing the levels, the expression and/or the
activity of leptin in said subject.
[0016] More particularly, increasing the levels or the expression
of leptin in a subject in need thereof may be performed by
administering to said subject an immuno-modulatory effective amount
of leptin or any homologues, derivatives, functional fragments or
mixture thereof, an expression vector comprising nucleic acid
sequence encoding for leptin or any functional fragments thereof or
a composition comprising the same.
[0017] According to a specifically preferred embodiment, the method
of the invention is particularly useful for shifting of the Th1/Th2
cell balance toward the pro-inflammatory cytokine producing cells a
mammalian subject suffering of an immune-related disorder.
[0018] More preferably, shifting of the Th1/Th2 cell balance toward
the pro-inflammatory cytokine producing cells may be particularly
advantageous for immune-related disorder such as malignant
proliferative disorder, a disorder caused by immuno-suppression and
an infection caused by a pathogenic agent.
[0019] According to one embodiment, a malignant proliferative
disorder may be any one of solid and non-solid tumor selected from
the group consisting of carcinoma, sarcoma, melanoma, leukemia and
lymphoma.
[0020] According to another particular embodiment, the method of
the invention may be advantageous for Hepatocellular carcinoma
(HCC).
[0021] In another preferred embodiment, the subject in need of
modulating the Th1/Th2 cell balance toward the pro-inflammatory
cytokine producing cells by the method of the invention may suffer
from any immuno-suppressive disorder, for example immune
suppression caused by infection of immunodeficiency virus,
preferably, HIV, or alternatively, immuno-suppression caused by
chemotherapy.
[0022] According to another embodiment, shifting of the Th1/Th2
cell balance toward the pro-inflammatory cytokine producing cells
by the method of the invention may be advantageous in a subject
suffering of an infection, for example infection caused by a
pathogenic agent selected from the group consisting of bacterial
pathogens, viruses, fungi, parasites and yeast.
[0023] The invention further provides for a method for the
treatment of an immune-related disorder in a subject in need
thereof, comprising the step of administering to said subject an
immuno-modulatory effective amount of leptin or any homologues,
derivatives, functional fragments or mixture thereof, an expression
vector comprising nucleic acid sequence encoding for leptin or any
functional fragments thereof or a composition comprising the
same.
[0024] In one embodiment, the effective amount administered to a
subject suffering from an immune-related disorder may be an amount
sufficient for shifting the Th1/Th2 cell balance toward
pro-inflammatory cytokine producing cells.
[0025] According to another embodiment, the method of the invention
is particularly applicable for the treatment of an immune-related
disorder such as any one of a malignant proliferative disorder, a
disorder caused by immuno-suppression and an infection caused by a
pathogenic agent.
[0026] More particularly, the method of the invention is
particularly applicable for the treatment of a malignant
proliferative disorder such as any one of solid and non-solid tumor
selected from the group consisting of carcinoma, sarcoma, melanoma,
leukemia and lymphoma.
[0027] According to a specifically preferred embodiment, the method
of the invention is for the treatment of Hepatocellular carcinoma
(HCC).
[0028] According to another embodiment, the method of the invention
is suitable for the treatment of immuno-suppression caused by
infection of immunodeficiency virus, preferably, HIV, or caused by
chemotherapy.
[0029] Still further, the method of the invention is intended for
the treatment of an infection caused by a pathogenic agent, for
example, bacterial pathogens, viruses, fungi, parasites and
yeast.
[0030] In another aspect, the invention relates to the use of
leptin or any homologues, derivatives, functional fragments or
mixture thereof, an expression vector comprising nucleic acid
sequence encoding for leptin or any, functional fragments thereof
for the preparation of a composition for shifting the Th1/Th2 cell
balance toward pro-inflammatory cytokine producing cells.
[0031] The invention further relates to the use of leptin or any
homologues, derivatives, functional fragments or mixture thereof,
an expression vector comprising nucleic acid sequence encoding for
leptin or any functional fragments thereof for the preparation of a
medicament for the treatment of an immune-related disorder.
[0032] According to one embodiment of said aspect, the
immune-related disorder may be any one of a malignant proliferative
disorder, a disorder caused by immuno-suppression and an infection
caused by a pathogenic agent.
[0033] Specifically, a malignant proliferative disorder may be any
one of solid and non-solid tumor selected from the group consisting
of carcinoma, preferably, Hepatocellular carcinoma (HCC), sarcoma,
melanoma, leukemia and lymphoma.
[0034] In another embodiment, the immune related disorder may be
immuno-suppression, for example, caused by infection of
immunodeficiency virus, preferably, HIV, or alternatively, by
chemotherapy.
[0035] In yet another embodiment, the immune related disorder may
be infection caused by a pathogenic agent selected from the group
consisting of bacterial pathogens, viruses, fungi, parasites and
yeast.
[0036] In a third aspect, the invention relates to a method for
immuno-modulation of the immune system resulted by shifting the
Th1/Th2 cell balance toward the anti-inflammatory cytokine
producing cells, in a subject in need thereof. Such method
comprises the step of decreasing the levels, the expression and/or
the activity of leptin in said subject.
[0037] According to one embodiment, decreasing the levels, the
expression or the activity of leptin in said subject by the method
of the invention may be performed by administering to a subject in
need thereof, an immuno-modulatory effective amount of any one of
an antibody specific for leptin and a nucleic acid sequence capable
of inhibiting the expression of leptin selected from the group
consisting of leptin anti-sense nucleic acid sequence, a ribozyme,
a small interfering RNA (siRNA) specific for leptin and a
composition comprising the same.
[0038] According to a specific embodiment, a subject may be a
mammalian subject suffering of an immune-related disorder.
[0039] More particularly, the immune-related disorder may be any
one of an inflammatory disorder, an autoimmune disorder, a
graft-rejection associated disorder and a fibrotic disorder.
[0040] In one embodiment, an inflammatory disorder may be an
intestinal inflammatory disease, preferably, an inflammatory bowel
diseases (IBD).
[0041] In another embodiment, the immune-related disorder may be a
fibrotic disorder, for example, hepatic fibrosis, cardiac fibrosis,
or colon fibrosis.
[0042] In yet another embodiment, shifting the Th1/Th2 cell balance
toward the anti-inflammatory cytokine producing cells, may be
performed in a subject suffering from an auto-immune disease such
as arthritis, diabetes or immune related infertility disorders.
[0043] The invention further provides for a method for the
treatment of an immune-related disorder in a subject in need
thereof. The method of the invention comprises the step of
administering to said subject an immuno-modulatory effective amount
of any one of an antibody specific for leptin and a nucleic acid
sequence capable of inhibiting the expression of leptin selected
from the group consisting of leptin anti-sense nucleic acid
sequence, a ribozyme, a small interfering RNA (siRNA) specific for
leptin and a composition comprising the same.
[0044] According to one embodiment, an effective amount may be an
amount sufficient for shifting the Th1/Th2 cell balance toward
anti-inflammatory cytokine producing cells.
[0045] In another embodiment, the method of the invention is
intended for the treatment of an immure-related disorder such as
inflammatory disorder, an autoimmune-disorder a graft-rejection
associated disorder or a fibrotic disorder.
[0046] According to a specific embodiment, the method of the
invention is particularly advantageous for the treatment of an
inflammatory disorder, preferably, an intestinal inflammatory
disease and most preferably, inflammatory bowel diseases (IBD).
[0047] According to another specific embodiment, the method of the
invention is suitable for the treatment of a fibrotic disorder such
as any one of hepatic fibrosis, cardiac fibrosis and colon
fibrosis.
[0048] Still further, the method of the invention may be applicable
for the treatment of auto-immune disease, for example, any one of
arthritis, diabetes and immune-related infertility disorders.
[0049] According to another aspect, the invention relates to the
use of any one of an antibody specific for leptin and a nucleic
acid sequence capable of inhibiting the expression of leptin
selected from the group consisting of leptin anti-sense nucleic
acid sequence, a ribozyme and a small interfering RNA (siRNA)
specific for leptin for the preparation of a composition for
shifting the Th1/Th2 cell balance toward anti-inflammatory cytokine
producing cells.
[0050] The invention further provides for the use of any one of an
antibody specific for leptin and a nucleic acid sequence capable of
inhibiting the expression of leptin selected from the group
consisting of leptin anti-sense nucleic acid sequence, a ribozyme,
a small interfering RNA (siRNA) specific for leptin for the
preparation of a medicament for the treatment of an immune-related
disorder.
[0051] According to one embodiment, an immune-related disorder may
be any one of an inflammatory disorder, an autoimmune-disorder, a
graft-rejection associated disorder and a fibrotic disorder.
[0052] More specifically, an inflammatory disorder may be an
intestinal inflammatory disease, preferably, inflammatory bowel
diseases (IBD).
[0053] In another embodiment, the immune related disorder may be a
fibrotic disorder such as hepatic fibrosis, cardiac fibrosis or
colon fibrosis.
[0054] In yet another embodiment, the immune-related disorder may
be an auto-immune disease, for example, arthritis, diabetes and
immune-related infertility disorders.
[0055] According to another aspect, the invention relates to a
method for the treatment of immune-related disorders in a mammalian
subject in need of such treatment, by manipulating NK T cell
population of said subject, wherein manipulation of said NK T cell
population results in modulation of the Th1/Th2 cell balance, said
method comprises the steps of: (a) obtaining NK T cells from said
subject; (b) ex vivo educating the NK T cells obtained in step (a)
such that the resulting educated NK T cells have the capability of
modulating the Th1/Th2 cell balance; and (c) reintroducing to said
subject the educated NK T cells obtained in step (b) which are
capable of modulating the Th1/Th2 cell balance.
[0056] According to one embodiment, ex vivo education of step (b)
may be performed by culturing said NK T cells in the presence of
(a) antigens associated with said immune-related disorder or any
combination thereof; (b) an antigen presenting cell, preferably,
DC; and (c) leptin or any homologues, derivatives, functional
fragments or mixture thereof, an expression vector comprising
nucleic acid sequence encoding for leptin or any functional
fragments thereof or a composition comprising the same.
[0057] The invention further provides for a therapeutic composition
for the treatment of an immune-related disorder in a mammalian
subject. The composition of the invention comprises as an effective
ingredient ex vivo educated autologous NK T cells capable of
modulating the Th1/Th2 cell balance, and optionally further
comprising pharmaceutically acceptable carrier, diluent, excipient
and/or additive.
[0058] According to one embodiment, the educated autologous NK T
cell used for the composition of the invention may be obtained by
ex vivo culture in the presence of: (a) antigens associated with
said immune-related disorder or any combination thereof; (b) an
antigen presenting cell, preferably, DC; and (c) leptin or any
homologues, derivatives, functional fragments or mixture thereof,
an expression vector comprising nucleic acid sequence encoding for
leptin or any functional fragments thereof or a composition
comprising the same.
BRIEF DESCRIPTION OF THE FIGURES
[0059] FIG. 1--Leptin Induces In-Vitro Proliferation of NKT
Cells
[0060] Histogram showing proliferation of NKT cells isolated from
experimental groups A-H. As shown by the figure, leptin induces a
significant increase in in-vitro proliferation of NKT lymphocytes
that are incubated with HCC-related antigens in the present of
DC's.
[0061] FIG. 2A-2B--Leptin Decrease HCC in T Cell Deficient Nude
Mice
[0062] Demonstrative photograph of a mouse that was not
administered leptin (FIG. 2A) five weeks after the subcutaneous
implantation of hepatocellular carcinoma showing a large tumor.
Mouse that was continuously administered leptin (FIG. 2B) developed
a significantly smaller tumor, with a large necrotic center.
[0063] FIG. 3 Leptin Significantly Decrease Tumor Size in T Cell
Deficient Nude Mice
[0064] Tumors of mouse group A that was administered leptin (top
row) were significantly small in size than tumors of mouse group C
that was not administered leptin (bottom row). The latter group
featured a 20% mortality, as compared to 0% in the former
group.
[0065] FIG. 4A-4B Leptin Induces an Intense Inflammatory Response
in Tumor Interphase Areas
[0066] Histological evaluation of excised tumors of group C mice
(not administered leptin) revealed a lack of inflammatory response
in interphase areas (FIG. 4A). In comparison, group A mice that
were administered leptin uniformly developed an intense
inflammatory response in tumor interphase areas (FIG. 4B).
[0067] FIG. 5--Leptin Induces a Significant Increase in Serum ALT
Activity 8 Hours Following Concanavalin A Infusion
[0068] Histogram demonstrate the ALT activity of four experimental
groups, con+leptin, con, leptin and control.
[0069] FIG. 6A-6C-- Leptin Induces a Significant Exacerbation of
Concanavalin-Induced Hepatitis
[0070] Hepatic histological sections showing that leptin induces a
significant exacerbation of concanavalin-induced hepatitis (FIG.
6C) in comparison to concanavalin alone (FIG. 6B). Leptin
administration by itself did not produce any hepatic damage (FIG.
6A).
[0071] FIG. 7--Leptin Significantly Increases the Ratio of In-Vitro
Splenocyte Secretion of IFN-.gamma. and IL10 (IFN-.gamma./IL10)
[0072] Histogram showing the IFN-.gamma./IL10 ratio in four
different experimental groups A-D including con+leptin, con, leptin
and control group, respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0073] A number of methods of the art of molecular biology are not
detailed herein, as they are well known to the person of skill in
the art. Such methods include site-directed mutagenesis, PCR
cloning, expression of cDNAs, analysis of recombinant proteins or
peptides, transformation of bacterial and yeast cells, transfection
of mammalian cells, and the like. Textbooks describing such methods
are e.g., Sambrook et al., Molecular Cloning A Laboratory. Manual,
Cold Spring Harbor Laboratory; ISBN; 0879693096, 1989, Current
Protocols in Molecular Biology, by F. M. Ausubel; ISBN: 047150338X,
John. Wiley & Sons, Inc. 1988, and Short Protocols in Molecular
Biology, by F. M. Ausubel et al., (eds.) 3rd ed. John Wiley &
Sons; ISBN: 0471137812, 1995. These publications are incorporated
herein in their entirety by reference. Furthermore, a number of
immunological techniques are not in each instance described herein
in detail, as they are well known to the person of skill in the
art. See e.g., Current Protocols in Immunology, Coligan et al.,
(eds), John Wiley & Sons. Inc., New York, N.Y.
[0074] Leptin is a hormone which has been shown to interact with
its cognate receptor, thereby initiating its cell-signaling
pathway. Several different leptin receptor isoforms are predicted
to exist, including a long form which has the highest level of
expression in regions of the hypothalamus, and specific regions
therein, including the arcuate nucleus and the dorso-medial
hypothalamus. In vitro and in vivo studies demonstrate that leptin
activates cytokine-like signal transduction by stimulating the
classic JAK-STAT pathway via the long receptor isoform [Ghilardi,
N. et al., Proc. Natl. Acad. Sci. USA. 93:6231-6235 (1997);
Baumann, H. et al., Proc Natl. Acad. Sci. USA 93:8374-8378 (1996);
Vaisse, C. et al., Nature Genetics 14:95-97 (1996)]. Lack of
functional leptin or of long form leptin receptors in the ob/ob and
db/db mice, respectively, causes severe obesity [Zhang, et al.,
Nature 372:425-432 (1994); Lee, G. H. et al., Nature 379:632-635
(1996); Chen, H. et al., Cell 84:491-495 (1996)]. The cloning of
the genes encoding leptin [Zhang (1994) ibid.,] and the leptin
receptor [Tartaglia, et al., 61183:1263-1271(1995)], and the study
of these proteins in vivo and in vitro, have dramatically
demonstrated the importance of this ligand-receptor system in the
normal regulation of body weight and energy balance.
[0075] In addition to this role which has been proposed to be its
primary function, circulating leptin also appears to play an
important role in the neuroendocrine axis [Ahima, R. S., et al.,
Nature 382:250-252 (1996)], including the regulation of
reproduction. Administration of exogenous leptin has been shown to
induce the onset of puberty in mice [U.S. patent application Ser.
No. 08/749,534, the teachings of which are incorporated herein by
reference in its entirety].
[0076] The inventors have now shown that leptin is involved in
immuno-modulation of the Th1/Th2 response, and particularly leads
to enhancement of the pro-inflammatory response. As shown by
Example 1, leptin induces NK T cell proliferation, therefore,
without being bound by any theory, the present inventors
hypothesize that leptin induces a pro-inflammatory response
probably via NK T cells.
[0077] Thus, in a first aspect, the present invention relates to a
method for immuno-modulation of the Th1/Th2 cell balance, in a
subject in need thereof, comprising the step of modulating the
levels, the expression and/or the activity of leptin in said
subject.
[0078] According to one embodiment, modulation of the Th1/Th2 cell
balance by the method of the invention may be performed by
increasing or decreasing the levels, the activity and/or the
expression of leptin in said subject.
[0079] As shown by the present invention leptin may act as a potent
immuno-modulator by modulating the Th1/Th2 balance in a subject
suffering from an immune-related disorder. However, it is to be
appreciated that the modulation processes regulated by leptin may
be further mediated by different components of the subject's immune
system, such as cellular immune reaction elements, humoral immune
reaction elements and cytokines. Therefore, leptin may play a dual
role in immune modulation by switching the immune response in the
immunogenic or tolerogenic directions. Thus, regulation of the
immune response by leptin depends on the environment of such immune
response, which is determined by different types of stimulations
and different signaling pathways. It is noteworthy that leptin is
involved in distinct immunoregulatory mechanisms, and modulates
different types of effector cells and the Th1/Th2 paradigm in
immune-mediated disorders.
[0080] According to a specific preferred embodiment, modulation of
the Th1/Th2 cell balance may be mediated by the activation of
immuno-regulatory cells selected from the group consisting of NK T
cells, antigen presenting cells and CD4.sup.+, CD25.sup.+ T cells,
and preferably, NK T cells, by leptin.
[0081] The findings of the invention therefore provide new
modalities by using leptin as an immuno-regulator agent.
[0082] It is therefore particularly interesting to note that NK T
cells, and particularly, NK1.1 T cells may be involved in keeping a
balance between anti-inflammatory and pro-inflammatory lymphocytes
via cytokines secretion, and/or killing, and may be involved in the
determination of T helper cell differentiation [Arase, H., et al.,
Eur. J. Immunol. 23: 307-310 (1993); Yoshimoto, T., et al., J. Exp.
Med. 179:1285-1295 (1994), MacDonald, H. R., et al., J. Exp. Med.
182:633-638 (1995), Seder, R. A. et al., Annu. Rev. Immuno.
12:635-673 (1994), Yoshimoto, T., et al., Science 270:1845-1847
(1995)]. Multiple signaling pathways were identified for NK1.1 T
cells activation. It is assumed that NK1.1.sup.+ T cells are not
stably polarized, and upon different triggers TCR engagement
triggers both Th1 and Th2 cytokine secretion from these cells
[Bendelac, A., et al., Annu. Rev. Immunol. 15:535-562 (1997);
Arase, H., et al., J. Immunol. 151:546 (1993); Kawamura, T., et
al., J. Immunol. 160:16-19 (1998), Chen, H., et al., J. Immonol.,
159:2240-2249 (1997); Arase, H., et al., Eur. J. Immunol. 23:
307-310 (1998); Yoshimoto, T., J. Exp. Med. 179: 1285-1295 (1994);
MacDonald, H. R., J. ibid., (1995)]. NK1.1R or IL12R engagement may
selectively promote the Th1 secretion paradigm [Bendelac, et al.
(1997) ibid.; Arase, H., et al., J. Exp. Med. 183:2391-2396 (1996);
Hayakawa, T., et al., J. Exp. Med. 176:269-274 (1992)].
[0083] Therefore, in one specific embodiment, the invention
provides for a method for immuno-modulation resulted by shifting of
the Th1/Th2 cell balance toward the pro-inflammatory cytokine
producing cells, in a subject in need thereof. Accordingly, this
method comprises the step of increasing the levels, the expression
and/or the activity of leptin in said subject.
[0084] More particularly, increasing the levels or the expression
of leptin in a subject in need thereof may be performed by
administering to said subject an immuno-modulatory effective amount
of leptin or any homologues, derivatives, functional fragments or
mixture thereof, an expression vector comprising nucleic acid
sequence encoding for leptin or any functional fragments thereof or
a composition comprising the same.
[0085] Homologues of leptin refer to proteins, in which one or more
of the amino acid residues of a natural leptin are replaced by
different amino acid residues, or are deleted, or one or more amino
acid residues are added to the natural sequence of leptin, without
changing considerably the activity of the resulting products as
compared with the wild type leptin. These homologues are prepared
by known synthesis and/or by site-directed mutagenesis techniques,
or any other known technique suitable therefore.
[0086] Any such homologue preferably has a sequence of amino acids
sufficiently duplicative of that of leptin, such as to have
substantially similar activity to leptin. One such activity may be
the ability of a leptin homologue to reduce the body weight of
ob/ob mice. Thus, it can be determined whether any given homologue
has substantially the same activity as leptin by means of routine
experimentation. In a specifically preferred embodiment, leptin
homologue is capable of modulating Th1/Th2 cell balance.
[0087] In a preferred embodiment, any such protein has at least 40%
sequence identity or homology with the sequence of either leptin.
More preferably, it has at least 50%, at least 60%, at least 70%,
at least 80% or, most preferably, at least 90% sequence identity or
homology thereto.
[0088] Homologues of leptin polypeptides, which can be used in
accordance with the present invention, or nucleic acid coding
therefore, include a finite set of substantially corresponding
sequences as substitution peptides or polynucleotides which can be
routinely obtained by one of ordinary skill in the art, without
undue experimentation, based on the teachings and guidance
presented herein. For a detailed description of protein chemistry
and structure, see Schulz, G. E. et al., Principles of Protein
Structure, Springer-Verlag, New York, 1978; and Creighton, T. E.,
Proteins: Structure and Molecular Properties, W.H. Freeman &
Co., San Francisco. 1983, which are hereby incorporated by
reference.
[0089] Preferred changes for homologues in accordance with the
present invention are what are known as "conservative"
substitutions. Conservative amino acid substitutions of leptin
polypeptides may include synonymous amino acids within a group
which have sufficiently similar physicochemical properties that
substitution between members of the group will preserve the
biological function of the molecule [Grantham, et al., Science
185:862-864 (1974)]. It is clear that insertions and deletions of
amino acids may also be made in the sequences of leptin without
altering its function, particularly if the insertions or deletions
only involve a few amino acids, e.g., under thirty, and preferably
under ten, and do not remove or displace amino acids which are
critical to a functional conformation, e.g., cysteine residues
[Anfinsen, et al., Science 181:223.230 (1973)]. Proteins produced
by such deletions and/or insertions come within the purview of the
present invention.
[0090] It should be noted that any homologue of leptin has an amino
acid sequence essentially corresponding to that of leptin. The term
"essentially corresponding to" is intended to comprehend proteins
with minor changes to the sequence of the natural protein which do
not affect the basic characteristics of the natural proteins,
particularly insofar as their ability to modulate the
immune-system, preferably, towards the pro-inflammatory response.
The type of changes which are generally considered to fall within
the "essentially corresponding to" language are those which would
result from conventional mutagenesis techniques of the DNA encoding
these proteins, resulting in a few minor modifications.
[0091] "Functional derivatives" as used herein cover derivatives of
leptin or its active fragments or fractions and its fusion
proteins, which may be prepared from the functional groups which
occur as side chains on the residues or the N- or C-terminal
groups, by means known in the art, and are included in the
invention as long as they remain pharmaceutically acceptable, i.e.
they do not destroy the activity of the protein which is
substantially similar to the activity of leptin, and do not confer
toxic properties on compositions containing it. These derivatives
may, for example, include polyethylene glycol side-chains which may
mask antigenic sites and extend the residence of leptin or its
active fractions in body fluids. Other derivatives include
aliphatic esters of the carboxyl groups, amides of the carboxyl
groups by reaction with ammonia or with primary or secondary
amines, N-acyl derivatives of free amino groups of the amino acid
residues formed with acyl moieties (e.g. alkanoyl or carbocyclic
aroyl groups) or O-acyl derivatives of free hydroxyl groups (for
example that of seryl or threonyl residues) formed with acyl
moieties.
[0092] As "functional fragments" of leptin and leptin fusion
proteins, the present invention covers any fragment or precursors
of the polypeptide chain of leptin, or fused proteins containing
any such fragment of leptin, alone or together with associated
molecules or residues linked thereto, e.g., sugar or phosphate
residues, or aggregates of any of the above derivatives, provided
said fraction has substantially similar activity to leptin.
[0093] Thus, by "functional fragments" is meant "fragments",
"variants", "analogs" or "derivatives" of the molecule. A
"fragment" of a molecule, such as any of the amino acid sequence of
leptin used by the present invention is meant to refer to any amino
acid subset of the molecule. A "variant" of such molecule is meant
to refer to a naturally occurring molecule substantially similar to
either the entire molecule or a fragment thereof. An "analog" of a
molecule is a homologous molecule from the same species or from
different species. By "functional" is meant having same biological
function, for example, required for immuno-modulation.
[0094] As indicated above, the terms derivatives and functional
derivatives as used herein mean peptides comprising the amino acid
sequence of leptin, with any insertions, deletions, substitutions
and modifications to the peptide that do not interfere with the
peptides ability to modulate Th1/Th2 response (hereafter referred
to as "derivative/s"). A derivative should maintain a minimal
homology to said amino acid sequence, e.g. even less than 30%. It
should be appreciated that the term "insertions" as used herein is
meant any addition of amino acid residues to the peptides used by
the invention, between 1 to 50 amino acid residues, preferably,
between 20 to 1 amino acid residues and most preferably, between 1
to 10 amino acid residues.
[0095] As indicated by said preferred embodiment, enhancing the
levels of leptin in a subject in need thereof may be accomplished
by the use of expression vectors encoding leptin or leptin
homologues, provided by gene therapy.
[0096] As used herein, the term "nucleic acid" refers to
polynucleotides such as deoxyribonucleic acid (DNA), and, where
appropriate, ribonucleic acid (RNA). The terms should also be
understood to include, as equivalents, analogs of either RNA or DNA
made from nucleotide analogs, and, as applicable to the embodiment
being described, single-stranded and double-stranded
polynucleotides. "Construct" or "vectors", as used herein,
encompases vectors such as plasmids, viruses, bacteriophage,
integratable DNA fragments, and other vehicles, which enable the
integration of DNA fragments into the genome of the host.
Expression vectors are typically self-replicating DNA or RNA
constructs containing the desired gene or its fragments, and
operably linked genetic control elements that are recognized in a
suitable host cell and effect expression of the desired genes.
These control elements are capable of effecting expression within a
suitable host. Generally, the genetic control elements can include
a prokaryotic promoter system or a eukaryotic promoter expression
control system. This typically include a transcriptional promoter,
an optional operator to control the onset of transcription,
transcription enhancers to elevate the level of RNA expression, a
sequence that encodes a suitable ribosome binding site, RNA splice
junctions, sequences that terminate transcription and translation
and so forth. Expression vectors usually contain an origin of
replication that allows the vector to replicate independently of
the host cell.
[0097] A vector may additionally include appropriate restriction
sites, antibiotic resistance or other markers for selection of
vector-containing cells. Plasmids are the most commonly used form
of vector but other forms of vectors which serves an equivalent
function and which are, or become, known in the art are suitable
for use herein. See, e.g., Pouwels et al., Cloning Vectors: a
Laboratory Manual (1985 and supplements), Elsevier, N.Y.; and
Rodriquez, et al. (eds.) Vectors: a Survey of Molecular Cloning
Vectors and their Uses, Buttersworth, Boston, Mass. (1988), which
are incorporated herein by reference.
[0098] It should be further appreciated that the invention further
encompasses the use of a host cell transformed or transfected with
a construct expressing leptin or any fragments thereof. Suitable
host cells include prokaryotes, lower eukaryotes, and higher
eukaryotes. Prokaryotes include gram negative and gram positive
organisms, e.g., E. coli and B. subtilis. Lower eukaryotes include
yeast, S. cerevisiae and Pichia, and species of the genus
Dictyostelium. Higher eukaryotes include established tissue culture
cell lines from animal cells, both of non-mammalian origin, e.g.,
insect cells and birds, and of mammalian origin, e.g., human and
other primate, and of rodent origin.
[0099] "Host cell" as used herein refers to cells which can be
recombinantly transformed with vectors constructed using
recombinant DNA techniques. A drug resistance or other selectable
marker is intended in part to facilitate the selection of the
transformants. Additionally, the presence of a selectable marker,
such as drug resistance marker may be of use in keeping
contaminating microorganisms from multiplying in the culture
medium. Such a pure culture of the transformed host cell would be
obtained by culturing the cells under conditions which require the
induced phenotype for survival.
[0100] As used herein, the term "transfection" means the
introduction of a nucleic acid, e.g., an expression vector, into a
recipient cells by nucleic acid-mediated gene transfer.
"Transformation", as used herein, refers to a process in which a
cell's genotype is changed as a result of the cellular uptake of
exogenous DNA or RNA.
[0101] "Cells", "host cells" or "recombinant cells" are terms used
interchangeably herein. It is understood that such terms refer not
only to the particular subject cells but to the progeny or
potential progeny of such a cell. Because certain modification may
occur in succeeding generation due to either mutation or
environmental influences, such progeny may not, in fact, be
identical to the parent cell, but are still included within the
scope of the term as used herein.
[0102] According to a specifically preferred embodiment, the method
of the invention is particularly useful for shifting of the Th1/Th2
cell balance toward the pro-inflammatory cytokine producing cells a
mammalian subject suffering of an immune-related disorder.
[0103] More preferably, shifting of the Th1/Th2 cell balance toward
the pro-inflammatory cytokine producing cells may be particularly
advantageous for immune-related disorder such as malignant
proliferative disorder, a disorder caused by immuno-suppression and
an infection caused by a pathogenic agent.
[0104] According to one embodiment, a malignant proliferative
disorder may be any one of solid and non-solid tumor selected from
the group consisting of carcinoma, sarcoma, melanoma, leukemia and
lymphoma. In cancerous situations, modulation of the NK T cells by
leptin, as showed by the Examples may be in the direction of
inducing a pro-inflammatory response. As used herein to describe
the present invention, "cancer", "tumor" and "malignancy" all
relate equivalently to a hyperplasia of a tissue or organ. If the
tissue is a part of the lymphatic or immune systems, malignant
cells may include non-solid tumors of circulating cells.
Malignancies of other tissues or organs may produce solid tumors.
In general, the methods and compositions of the present invention
may be used in the treatment of non-solid and solid tumors, for
example, carcinoma, melanoma, leukemia, and lymphoma.
[0105] Malignancies that may find utility in the present invention
can comprise but are not limited to hematological malignancies
(including leukemia, lymphoma and myeloproliferative disorders),
hypoplastic and aplastic anemia (both virally induced and
idiopathic), myelodysplastic syndromes, all types of paraneoplastic
syndromes (both immune mediated and idiopathic) and solid
tumors.
[0106] More specifically, according to a preferred embodiment,
leptin or a composition comprising the same, can be used for the
treatment or inhibition of non-solid cancers, e.g. hematopoietic
malignancies such as all types of leukemia, e.g. acute lymphocytic
leukemia (ALL), acute myelogenous leukemia (AML), chronic
lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML),
myelodysplastic syndrome (MDS), mast cell leukemia, hairy cell
leukemia, Hodgkin's disease, non-Hodgkin's lymphomas, Burkitt's
lymphoma and multiple myeloma, as well as for the treatment or
inhibition of solid tumors such as tumors in lip and oral cavity,
pharynx, larynx, paranasal sinuses, major salivary glands, thyroid
gland, esophagus, stomach, small intestine, colon, colorectum, anal
canal, liver, gallbladder, extraliepatic bile ducts, ampulla of
vater, exocrine pancreas, lung, pleural mesothelioma, bone, soft
tissue sarcoma, carcinoma and malignant melanoma of the skin,
breast, vulva, vagina, cervix uteri, corpus uteri, ovary, fallopian
tube, gestational trophoblastic tumors, penis, prostate, testis,
kidney, renal pelvis, ureter, urinary bladder, urethra, carcinoma
of the eyelid, carcinoma of the conjunctiva, malignant melanoma of
the conjunctiva, malignant melanoma of the uvea, retinoblastoma,
carcinoma of the lacrimal gland, sarcoma of the orbit, brain,
spinal cord, vascular system, hemangiosarcoma and Kaposi's
sarcoma.
[0107] According to another particular embodiment, as also shown by
the Examples, the method of the invention may be advantageous for
Hepatocellular carcinoma (HCC). Hepatocellular carcinoma (HCC) is
the seventh leading cause of cancer-related mortality in men and
the ninth in women. [Bosch, F. X. and Munoz, N. In: Etiology,
patology and treatment of hepatocellular carcinoma in America.
Advaces in applied technology series. Tabor E, Dibiscegile A M,
Purcell Rh (Eds.), Gulf, Houston (1991)]. The prevalence of the
disease is steadily increasing in the western world, mainly due to
a growing pool of longstanding chronic HCV carriers. An estimated
one million deaths are caused annually from HCC [El Serag, H. B. et
al., Ann. Intern. Med. 18:139(10):817-23 (2003)]. HCC is resistant
to systemic chemotherapy and radiation treatment.
Chemoembolisation, ethanol injection, radiofrequency ablasion, and
tumor resection offer a slight prognostic advantage and are mainly
used as palliative measures. Orthotopic liver transplantation may
offer cure in small tumors, but is rarely employed [Llovet, J. M.
et al., Lancet. 6:362(9399):1907-17 (2003)]. Therefore, modulation
of the immune response towards a pro-inflammatory response by the
use of leptin, is advantageous.
[0108] In another preferred embodiment, the subject in need of
modulating the Th1/Th2 cell balance toward the pro-inflammatory
cytokine producing cells by the method of the invention may suffer
from any immuno-suppressive disorder, for example immune
suppression caused by infection of immunodeficiency virus,
preferably, HIV, or alternatively, immuno-suppression caused by
chemotherapy. Chemotherapeutic treatment in malignancy is often
associated with life-threatening opportunistic infections,
resulting from potent inhibition of various arms of the immune
system. Often, the intensity and duration of chemotherapeutic
treatment are limited by these side effects. Stimulation of the
immune system, optionally by the co-administration of leptin may
enable treatment with higher doses and more potent combinations of
chemotherapeutic agents, thereby reducing the risks of
medication-induced immune suppression.
[0109] According to another embodiment, shifting of the Th1/Th2
cell balance toward the pro-inflammatory cytokine producing cells
by the method of the invention may be advantageous in a subject
suffering of an infection, for example infection caused by a
pathogenic agent.
[0110] Reference to pathogenic agents includes a prokaryotic
microorganism, a lower eukaryotic microorganism, a complex
eukaryotic organism, a virus, fungi, prions, parasite, yeast and
venoms.
[0111] A prokaryotic microorganism includes bacteria such as Gram
positive, Gram negative and Gram variable bacteria and
intracellular bacteria. Examples of bacteria contemplated herein
include the speices of the genera Treponema sp., Borrelia sp.,
Neisseria sp., Legionella sp., Bordetella sp., Escherichia sp.,
Salmonella sp., Shigella sp., Klebsiella sp., Yersinia sp., Vibrio
sp., Hemophilus sp., Rickettsia sp., Chlamydia sp., Mycoplasma sp.,
Staphylococcus sp., Streptococcus sp., Bacillus sp., Clostridium
sp., Corynebacterium sp., Proprionibacterium sp., Mycobacterium
sp., Ureaplasma sp. and Listeria sp.
[0112] Particularly preferred species include Treponema pallidum,
Borrelia burgdorferi, Neisseria gonorrhea, Neisseria meningitidis,
Legionella pneumophila, Bordetella pertussis, Escherichia coli,
Salmonella typhi, Salmonella typhimurium, Shigella dysenteriae,
Klebsiella pneumoniae, Yersinia pestis, Vibrio cholerae, Hemophilus
influenzae, Rickettsia rickettsii, Chlamydia trachomatis,
Mycoplasma pneumoniae, Staphylococcus aureus, Streptococcus
pneumoniae, Streptococcus pyogenes, Bacillus anthracis, Clostridium
botulinum, Clostridium tetani, Clostridium perfringens,
Corynebacterium diphtheriae, Proprionibacterium acnes,
Mycobacterium tuberculosis, Mycobacterium leprae and Listeria
monocytogenes.
[0113] A lower eukaryotic organism includes a yeast or fungus such
as but not limited to Pneumocystis carinii, Candida albicans,
Aspergillus, Histoplasma capsulatum, Blastomyces dermatitidis,
Cryptococcus neoformans, Trichophyton and Microsporum.
[0114] A complex eukaryotic organism includes worms, insects,
arachnids, nematodes, aemobe, Entamoeba histolytica, Giardia
lamblia, Trichomonas vaginalis, Trypanosoma brucei gambiense,
Trypanosoma cruzi, Balantidium coli, Toxoplasma gondii,
Cryptosporidium or Leishmania.
[0115] The term "viruses" is used in its broadest sense to include
viruses of the families adenoviruses, papovaviruses, herpesviruses:
simplex, varicella-zoster, Epstein-Barr, CMV, pox viruses:
smallpox, vaccinia, hepatitis B, rhinoviruses, hepatitis A,
poliovirus, rubellavirus, hepatitis C, arboviruses, rabiesvirus,
influenzaviruses A and B, measlesvirus, mumpsvirus, HIV, HTLV I and
II.
[0116] The term "fungi" includes for example, fungi that cause
diseases such as ringworm, histoplasmosis, blastomycosis,
aspergillosis, cryptococcosis, sporotrichosis, coccidioidomycosis,
paracoccidio-idoinycosis, and candidiasis.
[0117] The term parasite includes, but not limited to, infections
caused by somatic tapeworms, blood flukes, tissue roundworms,
ameba, and Plasmodium, Trypanosoma, Leishniania, and Toxoplasma
species.
[0118] The invention further provides for a method for the
treatment of an immune-related disorder in a subject in need
thereof, comprising the step of administering to said subject an
immuno-modulatory effective amount of leptin or any homologues,
derivatives, functional fragments or mixture thereof, an expression
vector comprising nucleic acid sequence encoding for leptin or any
functional fragments thereof or a composition comprising the
same.
[0119] As used herein in the specification and in the claims
section below, the term "treat" or treating and their derivatives
includes substantially inhibiting, slowing or reversing the
progression of a condition, substantially ameliorating clinical
symptoms of a condition or substantially preventing the appearance
of clinical symptoms of a condition.
[0120] As used herein, "an immuno-modulatory amount" or "an amount
sufficient to modulate the Th1/Th2 balance" means an amount
necessary to achieve a selected result. For example, an effective
amount of the composition of the invention will modulate the
Th1/Th2 balance toward pro-inflammatory cytokine producing
cells.
[0121] Thus, in one embodiment, the effective amount administered
to a subject suffering from an immune-related disorder may be an
amount sufficient for shifting the Th1/Th2 cell balance toward
pro-inflammatory cytokine producing cells.
[0122] According to another embodiment, the method of the invention
is particularly applicable for the treatment of an immune-related
disorder such as any one of a malignant proliferative disorder, a
disorder caused by immuno-suppression and an infection caused by a
pathogenic agent as described above.
[0123] More particularly, the method of the invention is
particularly applicable for the treatment of a malignant
proliferative disorder such as any one of solid and non-solid tumor
selected from the group consisting of carcinoma, sarcoma, melanoma,
leukemia and lymphoma.
[0124] According to a specifically preferred embodiment, the method
of the invention is for the treatment of Hepatocellular carcinoma
(HCC).
[0125] According to another embodiment, the method of the invention
is suitable for the treatment of immuno-suppression caused by
infection of immunodeficiency virus, preferably, HIV, or caused by
chemotherapy.
[0126] Still further, the method of the invention is intended for
the treatment of an infection caused by a pathogenic agent, for
example, bacterial pathogens, viruses, fungi, parasites and
yeast.
[0127] In another aspect, the invention relates to the use of
leptin or any homologues, derivatives, functional fragments or
mixture thereof, an expression vector comprising nucleic acid
sequence encoding for leptin or any functional fragments thereof
for the preparation of a composition for shifting the Th1/Th2 cell
balance toward pro-inflammatory cytokine producing cells.
[0128] The invention further relates to the use of leptin or any
homologues, derivatives, functional fragments or mixture thereof,
an expression vector comprising nucleic acid sequence encoding for
leptin or any functional fragments thereof for the preparation of a
medicament for the treatment of an immune-related disorder.
[0129] According to one embodiment of said aspect, the
immune-related disorder may be any one of a malignant proliferative
disorder, a disorder caused by immuno-suppression and an infection
caused by a pathogenic agent.
[0130] Specifically, a malignant proliferative disorder may be any
one of solid and non-solid tumor selected from the group consisting
of carcinoma, preferably, Hepatocellular carcinoma (HCC), sarcoma,
melanoma, leukemia and lymphoma.
[0131] In another embodiment, the immune related disorder may be
immuno-suppression, for example, caused by infection of
immunodeficiency virus, preferably, HIV, or alternatively, by
chemotherapy.
[0132] In yet another embodiment, the immune related disorder may
be infection caused by a pathogenic agent selected from the group
consisting of bacterial pathogens, viruses, fungi, parasites and
yeast.
[0133] The role of leptin in modulation of the Th1/Th2 response and
in induction of a pro-inflammatory response, enables the regulation
of such element, for example, by neutralizing its, for induction of
an anti-inflammatory response.
[0134] Therefore, in a third aspect, the invention relates to a
method for immuno-modulation of the immune system resulted by
shifting the Th1/Th2 cell balance toward the anti-inflammatory
cytokine producing cells, in a subject in need thereof. Such method
comprises the step of decreasing the levels, the expression and/or
the activity of leptin in said subject.
[0135] According to one embodiment, decreasing the levels, the
expression or the activity of leptin in said subject by the method
of the invention may be performed by administering to a subject in
need thereof, an immuno-modulatory effective amount of any one of
an antibody specific for leptin and a nucleic acid sequence capable
of inhibiting the expression of leptin selected from the group
consisting of leptin anti-sense nucleic acid sequence, a ribozyme,
a small interfering RNA (siRNA) specific for leptin and a
composition comprising the same.
[0136] The term "antibody" is meant to encompass polyclonal
antibodies, monoclonal antibodies (mAbs), chimeric antibodies
(e.g., humanized antibodies) and antibody fragments that retain the
biological activity of specific binding to leptin, such as Fab,
Fab', F(ab')2 and Fv. Also encompassed are single-chain antibodies
(sFvs). These antibody fragments lack the Fc portion of an intact
antibody, clear more rapidly from the circulation and can have less
non-specific tissue binding than an intact antibody. These
fragments are produced by well-known methods in the art, for
example by proteolytic cleavage with enzymes such as papain (to
produce Fab fragments) or pepsin (to produce F(ab')2 fragments.
[0137] Polyclonal antibodies are heterogeneous populations of
antibody molecules derived from the sera of animals immunized with
an antigen. A monoclonal antibody (mAb) contains a substantially
homogenous population of antibodies specific to antigens, which
population contains substantially similar epitope binding sites.
MAbs may be obtained by methods known to those skilled in the art.
See, for example Kohler and Milstein, Nature 256:495-497, 1975;
U.S. Pat. No. 4,376,110; Ausubel et al, eds., Current Protocols in
Molecular Biology, Green Publishing Assoc. and Wiley Interscience,
N.Y., 1987, 1992; and Harlow and Lane Antibodies: A Laboratory
Manual Cold Spring Harbor Laboratory, 1988; Colligan et al, eds.,
Current Protocols in Immunology, Greene Publishing Assoc. and Wiley
Interscience, N.Y., 1992, 1993; the contents of which references
are incorporated entirely herein by reference. Such antibodies can
be of any immunoglobulin class including IgG, IgM, IgE, IgA, and
any subclass thereof. A hybridoma producing a mAb of the present
invention can be cultivated in vitro, in situ, or in vivo.
Production of high titers of mAbs in vivo or in situ makes this the
presently preferred method of production.
[0138] Chimeric antibodies which include humanized antibodies, are
molecules wherein different portions of which are derived from
different animal species, such as those having variable regions
derived from a murine mAb and a human immunoglobulin constant
region. Chimeric antibodies are primarily used to reduce
immunogenicity in application and/or to increase yields in
production, for example. Chimeric antibodies and methods for their
production are known in the art [Cabilly, et al., Proc. Natl. Acad.
Sci. USA 81:3273-3277 (1984); Morrison, et al., Proc. Natl. Acad.
Sci. USA 81:6851-6855 (1984); Boulianne, et al., Nature 312:643-646
(1984)]. These references are entirely incorporated herein by
reference.
[0139] Typically, antibodies that may be used for reducing leptin
levels or function by the methods of the present invention are high
affinity anti-leptin antibodies, and fragments or regions thereof
that have potent inhibiting and/or neutralizing activity in vivo
against leptin. Such antibodies can include those generated by
immunization using purified recombinant leptin or peptide fragments
thereof.
[0140] Methods for determining antibody specificity and affinity
can be found in Harlow, et al., Antibodies: A Laboratory Manual,
Cold spring Harbor Laboratory Press, Cold. Spring Harbor, N.Y.,
1988; Colligan et al., eds., Current Protocols in Immunology,
Greene Publishing Assoc. and Wiley Interscience, N.Y., 1992, 1993;
and Muller, Meth. Enzymol., 92:589-601 1983; which references are
entirely incorporated herein by reference.
[0141] The generation of polyclonal antibodies against proteins is
described in Chapter 2 of Current Protocols in Immunology, Wiley
and Sons Inc. Monoclonal antibodies may be prepared from B cells
taken from the spleen or lymph nodes of immunized animals, in
particular rats or mice, by fusion with immortalized B cells under
conditions which favor the growth of hybrid cells. For fusion of
murine B cells, the cell line Ag-8 is preferred. The technique of
generating monoclonal antibodies is described in many articles and
textbooks, such as the above-noted Chapter 2 of Current Protocols
in Immunology. Spleen or lymph node cells of these animals may be
used in the same way as spleen or lymph node cells of
protein-immunized animals, for the generation of monoclonal
antibodies as described in Chapter 2 therein. The techniques used
in generating monoclonal antibodies are further described by Kohler
and Milstein, Nature 256:495-497, (1975), and in U.S. Pat. No.
4,376,110.
[0142] As indicated above, for future clinical applications, where
the anti-leptin antibody is a monoclonal antibody, it may be
improved, through a humanization process, to overcome the human
antibody to mouse antibody response. Rapid new strategies have been
developed recently for antibody humanization which may be applied
for such antibody. These technologies maintain the affinity, and
retain the antigen and epitope specificity of the original antibody
Rader, C., et al., Proc. Natl. Acad. Sci. 95:8910-8915 (1998);
Mateo, C., et al., Immunothechnology 3:71-81 (1997)]. A "humanized"
antibody, in which, for example animal (say murine) variable
regions are fused to human constant regions, or in which murine
complementarity-determining regions are grafted onto a human
antibody. Unlike, for example, animal derived antibodies,
"humanized" antibodies often do not undergo an undesirable reaction
with the immune system of the subject.
[0143] Thus, as used herein, the term "humanized" and its
derivatives refers to an antibody which includes any percent above
zero and up to 100% of human antibody material, in an amount and
composition sufficient to render such an antibody less likely to be
immunogenic when administered to a human being. It is being
understood that the term "humanized" reads also on human derived
antibodies or on antibodies derived from non human cells
genetically engineered to include functional parts of the human
immune system coding genes, which therefore produce antibodies
which are fully human.
[0144] Reducing the levels, expression and activity of leptin by
the method of the invention may be also achieved by the use of
particular nucleic acid sequences, such as anti-sense sequence,
siRNA and a catalytic nucleic acid sequence such as ribozyme,
specific for leptin. The term "siRNAs" refers to short interfering
RNAs. The term "RNA interference" or "RNAi" refers to the silencing
or decreasing of gene expression by siRNAs. It is the process of
sequence-specific, post-transcriptional gene silencing in animals
and plants, initiated by siRNA that is homologous in its duplex
region to the sequence of the silenced gene. The gene may be
endogenous or exogenous to the organism, present integrated into a
chromosome or present in a transfection vector that is not
integrated into the genome. The expression of the gene is either
completely or partially inhibited. RNAi may also be considered to
inhibit the function of a target RNA; the function of the target
RNA may be complete or partial. RNA interference (RNAi) is a
mechanism involving double-stranded RNA (dsRNA) molecules and
resulting in posttranscriptional sequence-specific silencing of
gene expression.
[0145] As indicated above, ribozymes may also be used. Ribozymes
are RNA molecules having an enzymatic activity which is able to
repeatedly cleave other separate RNA molecules in a nucleotide base
sequence specific manner. Several basic varieties of
naturally-occurring enzymatic RNAs are known presently. Each can
catalyze the hydrolysis of RNA phosphodiester bonds in-trans (and
thus can cleave other RNA molecules) under physiological
conditions. In general, enzymatic nucleic acids act by first
binding to a target RNA. Such binding occurs through the target
binding region of a enzymatic nucleic acid which is held in close
proximity to an enzymatic region or catalytic region of the
molecule that acts to cleave the target RNA. Thus, the enzymatic
nucleic acid first recognizes and then binds a target RNA through
complementary base-pairing, and once bound to the correct site,
acts enzymatically to cut the target RNA. Strategic cleavage of
such a target RNA will destroy its ability to direct synthesis of
an encoded protein, and according to the present invention, the
expression of leptin. After an enzymatic nucleic acid has bound and
cleaved its RNA target, it is released from that RNA to search for
another target and can repeatedly bind and cleave new targets.
Thus, a single ribozyme molecule is able to cleave many molecules
of target RNA. In addition, the ribozyme is a highly specific
inhibitor of gene expression, with the specificity of inhibition
depending not only on the base-pairing mechanism of binding to the
target RNA, but also on the mechanism of target RNA cleavage.
Single mismatches, or base-substitutions, near the site of cleavage
can completely eliminate catalytic activity of a ribozyme.
[0146] According to a specific embodiment, a subject may be a
mammalian subject suffering of an immune-related disorder.
[0147] More particularly, the immune-related disorder may be any
one of an inflammatory disorder, an autoimmune-disorder, a
graft-rejection associated disorder and a fibrotic disorder.
[0148] Therefore, in a further embodiment, antibodies, anti-sense,
siRNA and ribozymes specific for leptin, as described by the
invention may be useful for treatment of or amelioration of
inflammatory symptoms in any disease, condition or disorder where
immune and/or inflammation suppression is beneficial such as, but
not limited to, treatment of or amelioration of inflammatory
symptoms in the joints, musculoskeletal and connective tissue
disorders, or of inflammatory symptoms associated with
hypersensitivity, allergic reactions, asthma, atherosclerosis,
otitis and other otorhinolaryngological diseases, dermatitis and
other skin diseases, posterior and anterior uveitis,
conjunctivitis, optic neuritis, scleritis and other immune and/or
inflammatory ophthalmic diseases.
[0149] Diseases characterized by airway inflammation affect a
substantial proportion of the population. These diseases include
asthma and chronic obstructive pulmonary disease (COPD). In the
European Union, COPD and asthma, together with pneumonia, are the
third most common cause of death. The production of cytokines and
growth factors in response to irritants, infectious agents and
inflammatory mediators play an important role in the initiation,
perpetuation and inhibition of acute and chronic airway
inflammation.
[0150] Airway inflammation is associated with excessive production
and activity of several mediators and cytokines released by
inflammatory and resident cells in the airways. Now it is clear
that the epithelium is not only an important target for the action
of mediators of inflammation, but also an active participant in the
inflammatory process itself. Bronchial epithelial cells are able to
recruit inflammatory cells to the airways through the release of
chemoattractants, to direct inflammatory cell migration across the
epithelium through the expression of cell adhesion molecules, and
to regulate the inflammatory activity of other cells through the
release of mediators, like cytokines, chemokines, arachidonic acid
metabolities and relaxant and contractile factors.
[0151] In one embodiment, an inflammatory disorder may be an
intestinal inflammatory disease, preferably, an inflammatory bowel
diseases (IBD).
[0152] Inflammatory bowel diseases (IBD) are common
gastrointestinal disorders, that can be perceived as being the
result of a dysbalance between Th1-pro-inflammatory, and
Th2-anti-inflammatory subtypes of immune responses [Strober, W., et
al., Immunol Today 18:61-64 (1997); Neurath, M., et al., J. Exp.
Med. 183:2605-2616 (1996)].
[0153] There are several extra-intestinal manifestations that
accompany IBD, for example: autoimmune phenomena; immune complexes
have a role in target organ damage; and, immunosuppressive agents
such as glucocorticoids, azathioprine, methotrexate and cyclosporin
are used to alleviate the disease [Podolsky, D. K., et al., New
Engl. J. Med., 325:928-935(1991); Strober, W., et al., In Clinical
Immunology, Mosby, St. Louis. R. R. Rich, Editor, 1401-14281-2
(1995)]. Patients with IBD have antibodies against components of
colon cells and several different bacterial antigens. These
antigens gain access to the immune system as a consequence of
epithelial damage [Hibi, S., et al., Clin. Exp. Immunol. 54:163-168
(1983); Das, K. M., et al., Gastroenterology 98:464-69 (1990)].
Abnormalities of T cell-mediated immunity, including coetaneous
anergy and diminished responsiveness to T cell stimuli, have also
been described in these patients [Chiba, M., et al. Gut, 22:177-182
(1981); Raedler, A., et al., Clin. Exp. Immunol. 60:518-526
(1985)]. In addition, changes in mucosal cell mediated immunity
were identified, including increased concentrations of mucosal IgG
cells and changes in T cells subsets, suggesting antigen
stimulation [Dasgupta, A., et al., Gut 35:1712-17 (1994);
Takahashi, F., et al., J. Clin. Invest. 76:311-318 (1985)].
Exposure of target antigens after infectious, immune, or toxic
damage, leads to activation of mucosal immune cells resulting in
cytokines that lead to mucosal inflammatory response [Neurath, M.,
et al., J. Exp. Med., 183:2605-2616 (1996)]. Secretion of
pro-inflammatory cytokines such as IFN.gamma., contributes to an
increase in mucosal permeability, and has been described in animal
models of IBD [Strober, W., et al., Immunol. Today 18:61-64.
(1997)]. Similarly, an increase in collagen synthesis mediated by
IL1 and IL6 can be detected in these animals [Strober, W., et al.,
ibid.]. A Th1-mediated granulomatous colitis model has been
established by the adoptive transfer of normal CD45RB T cells from
Balb/C mice into CB-17 scid mice. CD4 cells from CD45RB were shown
to prevent the disease when injected together with the CD45RB
population. This prevention could be reversed by adding antibodies
to TGF.beta.1 [Sadlack, B., et al., Cell 75:253-261 (1993); Powrie,
F., et al., Immunity 1:553-562 (1994)].
[0154] Furthermore, the invention provides a use of antibody,
anti-sense, siRNA and ribozyme specific for leptin, wherein said
immune-mediated disorder comprises allergy, such as asthma or
parasitic disease, or use according to the invention wherein said
immune-mediated disorder comprises an overly strong immune response
directed against an infectious agent, such as a virus or bacterium.
Often in most of these diseases production of autoreactive
antibodies and/or autoreactive T lymphocytes can be found mounting
or being part of a too strong immune response. This is for example
seen with parasitic disease, where IgE production is overly strong
or which disease is Th2 dependent, and detrimental for the
organism, but also with (myco) bacterial infections such as TBC or
leprosy. An autoimmune response may also occur as manifestation of
viral or bacterial infection and may result in severe tissue
damage, for example destructive hepatitis because of Hepatitis B
virus infection, or as seen with lymphocytic choriomeningitis virus
(LCMV) infections.
[0155] In another preferred embodiment, decreasing the levels or
activity of leptin by the methods of the invention are useful for
treatment of or amelioration of an autoimmune disease such as, but
not limited to, Eaton-Lambert syndrome, Goodpasture's syndrome,
Greave's disease, Guillain-Barr syndrome, autoimmune hemolytic
anemia (AIHA), hepatitis, insulin-dependent diabetes mellitus
(IDDM), systemic lupus erythematosus (SLE), multiple sclerosis
(MS), myasthenia gravis, plexus disorders e.g. acute brachial
neuritis, polyglandular deficiency syndrome, primary biliary
cirrhosis, rheumatoid arthritis, scleroderma, thrombocytopenia,
thyroiditis e.g. Hashimoto's disease, Sjbgren's syndrome, allergic
purpura, psoriasis, mixed connective tissue disease, polymyositis,
dermatomyositis, vasculitis, polyarteritis nodosa, polymyalgia
rheumatica, Wegener's granulomatosis, Reiter's syndrome, Behget's
syndrome, ankylosing spondylitis, pemphigus, bullous pernphigoid,
dennatitis herpetiformis, insulin dependent diabetes, inflammatory
bowel disease, ulcerative colitis and Crohn's disease.
[0156] The invention further provides for a method for the
treatment of an immune-related disorder in a subject in need
thereof. The method of the invention comprises the step of
administering to said subject an immuno-modulatory effective amount
of any one of an antibody specific for leptin and a nucleic acid
sequence capable of inhibiting the expression of leptin selected
from the group consisting of leptin anti-sense nucleic acid
sequence, a ribozyme, a small interfering RNA (siRNA) specific for
leptin and a composition comprising the same.
[0157] It should be noted that composition dosages administered by
the methods of the invention may be in any amount that sufficient
to modulate the Th1/Th2 balance. It is understood by the skilled
artisan that the preferred dosage would be individualized to the
patient following good laboratory practices and standard medical
practices. As used herein, "an amount sufficient to modulate the
Th1/Th2 balance" means an amount necessary to achieve a selected
result. For example, an effective amount of the composition of the
invention will modulate the Th1/Th2 balance toward
anti-inflammatory cytokine producing cells.
[0158] Thus, according to one embodiment, an effective amount may
be an amount sufficient for shifting the Th1/Th2 cell balance
toward anti-inflammatory cytokine producing cells.
[0159] In another embodiment, the method of the invention is
intended for the treatment of an immune-related disorder such as
inflammatory disorder, an autoimmune-disorder a graft-rejection
associated disorder or a fibrotic disorder.
[0160] According to a specific embodiment, the method of the
invention is particularly advantageous for the treatment of an
inflammatory disorder, preferably, an intestinal inflammatory
disease and most preferably, inflammatory bowel diseases (IBD).
[0161] According to another specific embodiment, the method of the
invention is suitable for the treatment of a fibrotic disorder such
as any one of hepatic fibrosis, cardiac fibrosis and colon
fibrosis.
[0162] Still further, the method of the invention may be applicable
for the treatment of auto-immune disease, for example, any one of
arthritis, diabetes and immune-related infertility disorders.
[0163] According to another aspect, the invention relates to the
use of any one of an antibody specific for leptin and a nucleic
acid sequence capable of inhibiting the expression of leptin
selected from the group consisting of leptin anti-sense nucleic
acid sequence, a ribozyme and a small interfering RNA (siRNA)
specific for leptin for the preparation of a composition for
shifting the Th1/Th2 cell balance toward anti-inflammatory cytokine
producing cells.
[0164] The invention further provides for the use of any one of an
antibody specific for leptin and a nucleic acid sequence capable of
inhibiting the expression of leptin selected from the group
consisting of leptin anti-sense nucleic acid sequence, a ribozyme,
a small interfering RNA (siRNA) specific for leptin for the
preparation of a medicament for the treatment of an immune-related
disorder.
[0165] According to one embodiment, an immune-related disorder may
be any one of an inflammatory disorder, an autoimmune-disorder, a
graft-rejection associated disorder and a fibrotic disorder.
[0166] More specifically, an inflammatory disorder may be an
intestinal inflammatory disease, preferably, inflammatory bowel
diseases (IBD).
[0167] In another embodiment, the immune related disorder may be a
fibrotic disorder such as hepatic fibrosis, cardiac fibrosis or
colon fibrosis.
[0168] In yet another embodiment, the immune-related disorder may
be an auto-immune disease, for example, arthritis, diabetes and
immune-related infertility disorders.
[0169] Thus, in yet a further aspect, the invention relates to a
method for the treatment of immune-related disorders in a mammalian
subject in need of such treatment, by manipulating NK T cell
population of said subject, wherein manipulation of said NK T cell
population results in modulation of the Th1/Th2 cell balance, said
method comprises the steps of (a) obtaining NK T cells from said
subject; (b) ex vivo educating the NK T cells obtained in step (a)
such that the resulting educated NK T cells have the capability of
modulating the Th1/Th2 cell balance; and (c) re-introducing to said
subject the educated NK T cells obtained in step (b) which are
capable of modulating the Th1/Th2 cell balance.
[0170] According to one embodiment, ex vivo education of step (b)
may be performed by culturing said NK T cells in the presence of:
(a) antigens associated with said immune-related disorder or any
combination thereof; (b) an antigen presenting cell, preferably,
DC; and (c) leptin or any homologues, derivatives, functional
fragments or mixture thereof, an expression vector comprising
nucleic acid sequence encoding for leptin or any functional
fragments thereof or a composition comprising the same.
[0171] The NK T cells educated by the method of the invention can
be obtained from bone marrow, liver, spleen, or uterus, but can
also be obtained, from the peripheral blood, by cytopheresis, a
procedure by which a large number of white cells are obtained,
while other blood components are being simultaneously transferred
back to the subject.
[0172] It should be noted that several cell types appear to be
capable of serving as APC, including dendritic cells (DC),
activated B cells, and activated macrophages. In accordance with
the invention the APCs used for co-cultering with NK T cells, are
preferably autologous cells and in some illustrative preferred
embodiments the antigen-presenting cell may be a dendritic cell
(DC). It is understood that one of skill in the art will recognize
that other antigen presenting cells may be useful in the invention,
such as B cells activated by lipopolysaccharide, whole spleen
cells, peripheral blood macrophages, fibroblasts or
non-fractionated peripheral blood mononuclear cells (PBMC).
Therefore, the invention is not limited to the exemplary cell types
which are specifically mentioned and exemplified herein.
[0173] Co-culturing of the NK T cells in the presence of peripheral
lymphocytes from patients suffering from the same immune-related
disorder or from the treated subject, is also contemplated in the
present invention. In order to obtain lymphocytes from a subject,
particularly human subject, blood is drawn from the patient by
cytopheresis methods as described above.
[0174] As indicated above, the NK T cells are co-cultured with
APC's in the presence of leptin, and antigens associated with the
immune related disorder in which the subject suffers from.
[0175] It should be appreciated that antigens associated with an
immune-related disorder can be native or, non-native with regards
to the subject. They can be natural or synthetic, modified or
unmodified, whole or fragments thereof. Fragments can be derived
from synthesis as fragments or by digestion or other means of
modification to create fragments from larger entities. Such antigen
or antigens comprise but are not limited to proteins,
glycoproteins, enzymes, antibodies, histocompatibility
determinants, ligands, receptors, hormones, cytokines, cell
membranes, cell components, viruses, viral components, viral
vectors, non-viral vectors, whole cells, tissues or organs. The
antigen can consist of single molecules or mixtures of diverse
individual molecules. The antigen can present itself within the
context of viral surface, cellular surface, membrane, matrix, or
complex or conjugated with a receptor, ligand, antibody or any
other binding partner. Such antigen or antigens can be introduced
to the subject alone or with agent or agents that could further
contribute to uptake, stability, reactivity or targeting.
[0176] Polymerization and degradation, fractionation and chemical
modification are all capable of altering the properties of a
particular antigen in terms of potential immune responses. These
small segments, fragments or epitopes can either be isolated or
synthesized.
[0177] As a non-limiting example, such antigen may be combination
of different antigens derived from body extracts, preferably of the
subject to be treated or from a subject suffering of the same
disorder.
[0178] The invention further provides for a therapeutic composition
for the treatment of an immune-related disorder in a mammalian
subject. The composition of the invention comprises as an effective
ingredient ex vivo educated autologous NK T cells capable of
modulating the Th1/Th2 cell balance, and optionally further
comprising pharmaceutically acceptable carrier, diluent, excipient
and/or additive.
[0179] According to one embodiment, the educated autologous NK T
cell used for the composition of the invention may be obtained by
ex vivo culture in the presence of: (a) antigens associated with
said immune-related disorder or any combination thereof, (b) an
antigen presenting cell, preferably, DC; and (c) leptin or any
homologues, derivatives, functional fragments or mixture thereof,
an expression vector comprising nucleic acid sequence encoding for
leptin or any functional fragments thereof or a composition
comprising the same.
[0180] Methods for in vitro storage, growth or expansion of cells
prior to education or to transfer of the cells to the treated
subject, are well known to practitioners of the art. When the
educated NK T cells intended for use in a transfer are derived from
a donor, these cells may also undergo storage, growth or expansion
in vivo or in vitro as described above.
[0181] It is to be appreciated that the NK T cells may be educated
in vivo as well, via any of the methods described above, they can
be modulated prior to or at any point of time following exposure to
the APC, leptin and antigens related to said disorder.
[0182] Cell therapy may be by injection, e.g., intravenously, or by
any of the means described herein above. Neither the time nor the
mode of administration is a limitation on the present invention.
Cell therapy regimens may be readily adjusted taking into account
such factors as the possible cytotoxicity of the educated cells,
the stage of the disease and the condition of the patient, among
other considerations known to those of skill in the art.
[0183] It should be noted that any of the components used by the
different methods of the invention, e.g., leptin or any functional
fragments thereof, construct encoding leptin, host cells encoding
said constructs, educated NK T cells or alternatively, antibody,
anti-sense, siRNA and ribozyme specific for leptin, may by
administered in a single dose, or alternatively in multiple doses.
These components may be administered by a single route of
administration or alternatively, by at least two different routes
of administration.
[0184] The leptin or any functional fragments thereof, construct
encoding leptin, host cells encoding said constructs, educated NK T
cells or alternatively, antibody, anti-sense, siRNA and ribozyme
specific for leptin, may be administered directly to the subject to
be treated or, depending on the size of the compound, it may be
desirable to conjugate them to a carrier prior to their
administration. Therapeutic formulations may be administered in any
conventional dosage formulation. Formulations typically comprise at
least one active ingredient, as defined above, together with one or
more acceptable carriers thereof.
[0185] Each carrier should be both pharmaceutically and
physiologically acceptable in the sense of being compatible with
the other ingredients and not injurious to the patient.
Formulations include those suitable for oral, rectal, nasal, or
parenteral (including subcutaneous, intramuscular, intravenous and
intradermal) administration. The formulations may conveniently be
presented in unit dosage form and may be prepared by any methods
well known in the art of pharmacy. The nature, availability and
sources, and the administration of all such compounds including the
effective amounts necessary to produce desirable effects in a
subject are well known in the art and need not be further described
herein.
[0186] More specifically, the said leptin or any functional
fragments thereof, construct encoding leptin, host cells encoding
said constructs, educated NK T cells or alternatively, antibody,
anti-sense, siRNA and ribozyme specific for leptin, may be
administered by a route selected from oral, intravenous,
parenteral, transdermal, subcutaneous, intravaginal, intranasal,
mucosal, sublingual, topical and rectal administration and any
combinations thereof.
[0187] Although the method of the invention is particularly
intended for the treatment of immune-related disorders in humans,
other mammals are included. By way of non-limiting examples,
mammalian subjects include monkeys, equines, cattle, canines,
felines, mice, rats and pigs.
[0188] The leptin or any functional fragments thereof, construct
encoding leptin, host cells encoding said constructs, educated
cells or compositions thereof, may be administered in a single
dose, or alternatively in multiple doses. These components may be
administered by a single route of administration or alternatively,
by at least two different routes of administration. More
specifically, said components may be administered by a route
selected from oral, intravenous, parenteral, transdermal,
subcutaneous, intravaginal, intranasal, mucosal, sublingual,
topical and rectal administration and any combinations thereof.
[0189] For treating a mammalian subject suffering of an
immune-related disorder, for example, cancer, the leptin or any
functional fragments thereof, construct encoding leptin, host cells
encoding said constructs or educated cells, used by the method of
the invention can be administered in a variety of ways. By way of a
non-limiting example, these components, may be delivered
intravenously, or into a body cavity adjacent to the location of a
solid tumor, such as the intraperitoneal cavity, or injected
directly into or adjacent to a solid tumor.
[0190] It should be noted that all components and compositions used
by the methods of the invention may optionally include
sustained-release matrix, such as biodegradable polymers, to form
therapeutic compositions. A sustained-release matrix, as used
herein, is a matrix made of materials, usually polymers, which are
degradable by enzymatic or acid/base hydrolysis or by dissolution.
Once inserted into the body, the matrix is acted upon by enzymes
and body fluids. The sustained-release matrix desirably is chosen
from biocompatible materials such as liposomes, Polylactides
(polylactic acid), polyglycolide (polymer of glycolic acid),
polylactide co-glycolide (co-polymers of lactic acid and glycolic
acid) polyanhydrides, poly(ortho)esters, polypeptides, hyaluronic
acid, collagen, chondroitin sulfate, carboxylic acids, fatty acids,
phospholipids, polysaccharides, nucleic acids, polyamino acids,
amino acids such as phenylalanine, tyrosine, isoleucine,
polynucleotides and polyvinylpyrrolidone.
[0191] The immuno-modulating pharmaceutical compositions according
to the present invention may be a solid, liquid or aerosol and may
be administered by any known route of administration. Examples of
solid therapeutic compositions include pills, creams, and
implantable dosage units. The pills may be administered orally or
the therapeutic creams may be administered topically.
[0192] The implantable dosage units may be administered locally,
for example at a tumor site, or may be implanted for systemic
release of the therapeutic composition, for example subcutaneously.
Examples of liquid compositions include compositions adapted for
injection subcutaneously, intravenously, intraarterially, and
compositions for topical and intraocular administration. Examples
of aerosol compositions include inhaler composition for
administration to the lungs.
[0193] The leptin or any functional fragments thereof, construct
encoding leptin, host cells encoding said constructs or educated
cells, used by the different methods of the invention can be
administered by standard routes. In general, the combinations may
be administered by the topical (including buccal and sublingual),
or parenteral (including subcutaneous, intraperitoneal,
intramuscular, intravenous, intradermal, intracerebral,
intracerebroventricular, intracranial, intraspinal, intratracheal,
and epidural), transdermal, intravaginal, intrauterine, oral,
rectal, ophthalmic (including intravitreal or intracameral), or
intranasal administration. Osmotic mini-pumps may also be used to
provide controlled delivery of high concentrations of leptin, or
leptin derivatives, to the site of interest, such as directly into
a metastatic growth.
[0194] The magnitude of therapeutic dose of the composition of the
invention will of course vary with the group of patients (age, sex,
etc.), the nature of the condition to be treated and with the route
administration and will be determined by the attending
physician.
[0195] The pharmaceutical forms suitable for injection use include
sterile aqueous solutions or dispersions and sterile powders for
the extemporaneous preparation of sterile injectable solutions or
dispersions. In all cases the form must be sterile and must be
fluid to the extent that easy syringeability exists. It must be
stable under the conditions of manufacture and storage and must be
preserved against the contaminating action of microorganisms, such
as bacteria and fungi.
[0196] The prevention of the action of microorganisms can be
brought about by various antibacterial and antifungal agents, for
example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal,
and the like. In many cases, it will be preferable to include
isotonic agents, for example, sugars or sodium chloride. Prolonged
absorption of the injectable compositions can be brought about by
the use in the compositions of agents delaying absorption, for
example, aluminum monostearate and gelatin.
[0197] Sterile injectable solutions are prepared by incorporating
the active compounds in the required amount in the appropriate
solvent with various of the other ingredients enumerated above, as
required, followed by filtered sterilization. Generally,
dispersions are prepared by incorporating the various sterilized
active ingredients into a sterile vehicle which contains the basic
dispersion medium and the required other ingredients from those
enumerated above.
[0198] In the case of sterile powders for the preparation of the
sterile injectable solutions, the preferred method of preparation
are vacuum-drying and freeze drying techniques which yield a powder
of the active ingredient plus any additional desired ingredient
from a previously sterile-filtered solution thereof.
[0199] The pharmaceutical compositions of the invention generally
comprise a buffering agent, an agent which adjusts the osmolarity
thereof, and optionally, one or more pharmaceutically acceptable
carriers, excipients and/or additives as known in the art.
Supplementary active ingredients can also be incorporated into the
compositions. The carrier can be solvent or dispersion medium
containing, for example, water, ethanol, polyol (for example,
glycerol, propylene glycol, and liquid polyethylene glycol, and the
like), suitable mixtures thereof, and vegetable oils. The proper
fluidity can be maintained, for example, by the use of a coating,
such as lecithin, by the maintenance of the required particle size
in the case of dispersion and by the use of surfactants.
[0200] Local administration to the area in need of treatment is
also included and may be achieved by, for example, local infusion
during surgery, topical application, direct injection into the
inflamed joint, directly onto the eye, etc.
[0201] For oral administration, the pharmaceutical preparation may
be in liquid form, for example, solutions, syrups or suspensions,
or in solid form as tablets, capsules and the like. For
administration by inhalation, the compositions are conveniently
delivered in the form of drops or aerosol sprays. For
administration by injection, as indicated above, the formulations
may be presented in unit dosage form, e.g., in ampoules or in
multi-dose containers with an added preservative.
[0202] The compositions of the invention can also be delivered in a
vesicle, for example, in liposomes. In another embodiment, the
compositions can be delivered in a controlled release system.
[0203] The amount of the therapeutic or pharmaceutical composition
of the invention which is effective in the treatment of a
particular disease, condition or disorder will depend on the nature
of the disease, condition or disorder and can be determined by
standard clinical techniques. In addition, in vitro assays as well
in vivo experiments may optionally be employed to help identify
optimal dosage ranges. The precise dose to be employed in the
formulation will also depend on the route of administration, and
the seriousness of the disease, condition or disorder, and should
be decided according to the judgment of the practitioner and each
patient's circumstances. Effective doses may be extrapolated from
dose-response curves derived from in vitro or animal model test
systems.
[0204] Disclosed and described, it is to be understood that this
invention is not limited to the particular examples, methods steps,
and compositions disclosed herein as such methods steps and
compositions may vary somewhat. It is also to be understood that
the terminology used herein is used for the purpose of describing
particular embodiments only and not intended to be limiting since
the scope of the present invention will be limited only by the
appended claims and equivalents thereof.
[0205] It must be noted that, as used in this specification and the
appended claims, the singular forms. "a", "an"and "the" include
plural referents unless the content clearly dictates otherwise.
[0206] Throughout this specification and the Examples and claims
which follow, unless the context requires otherwise, the word
"comprise", and variations such as "comprises" and "comprising",
will be understood to imply the inclusion of a stated integer or
step or group of integers or steps but not the exclusion of any
other integer or step or group of integers or steps.
[0207] The following examples are representative of techniques
employed by the inventors in carrying out aspects of the present
invention. It should be appreciated that while these techniques are
exemplary of preferred embodiments for the practice of the
invention, those of skill in the art, in light of the present
disclosure, will recognize that numerous modifications can be made
without departing from the spirit and intended scope of the
invention.
EXAMPLES
Experimental Procedures
NKT Lymphocyte and Dendritic Cell Isolation
[0208] Donor mice were sacrificed at day 1 of the experiment and
splenic lymphocytes were isolated and red blood cells removed as
previously described [Trop, S. et al., Hepatology 29(3):746-55
(1999)]. Spleens were crushed through a stainless mesh (size 60,
Sigma Chemical Co., St. Louis Mo.). Cell suspension was placed in a
50 ml tube for 3 minutes and washed twice in cold PBS (1,250 rpm
for 10 minutes), and debris removed. Cells were re-suspended in
PBS, and placed through a nylon mesh presoaked in PBS, and unbound
cells were collected. Cells were washed twice in 45 ml PBS (1,250
rpm at room temperature). For splenocyte isolation, 20 ml of
Histopaque 1077 (Sigma Diagnostics, St. Louis, Mo.) were slowly
placed underneath the cells suspended in 7 ml of PBS, in a 50-ml
tube. Tubes were centrifuged at 1,640 rpm for 15 minutes at room
temperature. Cells at the interface were collected, diluted in a
50-ml tube, and washed twice with ice-cold PBS (1,250 rpm for 10
minutes). The viability by trypan blue staining was expected to be
more than 95%. Cell separation was performed using Magnetic Cell
Sorting (MACS). NKT cells were isolated using both anti CD3 and
anti-NK1.1 beads, while dendritic cells were isolated using anti
CD11a beads, in accordance with the manufacturer's instructions
(Miltenyl Biotec, Bergisch Gladbach, Germany).
HCC Cell Culture
[0209] Mouse hepatoma cell line HEPA 1-6 (CRL 1830), was grown in
culture as monolayers in a medium supplemented with nonessential
aminoacids and 10% heat inactivated fetal bovine serum.
[0210] The human hepatoma cell line Hep-3B which secretes HBsAg,
was grown in culture as monolayers, in medium supplemented with
non-essential amino acids and 10% heat inactivated fetal bovine
serum.
Preparation of HCC Lysate
[0211] 0.4.times.10.sup.6 HEPA 1-6 or HEP-3B cells were separated,
placed in Eppendorf tubes, and centrifuged at 250 g for 5 minutes.
The pellet was separated and subjected to three cycles of
freeze-thaw in liquid nitrogen. Protein quantification was
performed using commercial kits, following manufacturer's
instructions.
NKT Proliferation Using Radioactive Thymidine Incorporation
[0212] Isolated NKT lymphocytes and dendritic cells were cultured
in microwell plates (Sterilin co.), with or without HCC related
antigens and elevated doses of leptin, in a total volume of 0.2 ml
RPMI 1640 culture medium, supplemented with 100 mg/ml penicillin,
100 mg/ml streptomycin, 2 mM L-glutamine, with 5.times.10.sup.-5 M
2ME, and 10% FCS. After 24 h in a 37.degree. C. humidified 5%
CO.sub.2 incubator, 1 mmCi of .sup.3H TdR (5 Ci/nmol, Nuclear
Research Center, Negev, Israel) was added to each well. Cells were
collected 16 h later on paper filters, using a multiple sample
harvester (Titertek Cell Harvester 530; Flow Laboratories, McClean,
Va.). Radioactivity was measured by a liquid scintillation counter.
Background results were subtracted.
Cytokine Measurement
[0213] The content of each plate was centrifuged and the
supernatant fluid was collected. Supernatant cytokine levels were
measured by a "sandwich" ELISA method, using Genzyme Diagnostic
kits (Genzyme Diagnostics, MA, USA) according to the manufacturer's
instructions.
STAT and SMAD Western Blot Analysis
[0214] Expression of the transcription factors STAT (signal
transducer and activator of transcription) 1,3,4 and 6, p-STAT
1,3,4,6, and SMAD and p-SMAD 1-4 in splenocytes was determined by
Western blot analysis of protein extraction of splenocytes from
each plate. Splenocytes were lysed in 100 .mu.l of lysis solution
(Sigma). Proteins (100 .mu.g/lane) were resolved by electrophoresis
on SDS-polyacrylamide (7.5%) gels, and electroblotted to
nitrocellulose membranes (Schleicher & Scuell, Germany).
Probing with a polyclonal rabbit anti-mouse antibody for the
different tested STAT and SMAD proteins (Santa Cruz Biothechnology)
was followed by addition of horseradish peroxidase-conjugated goat
anti-rabbit IgG (Jackson Immuno Research, PA, USA).
Determination of the Presence of Leptin Receptors on NKT Cells
[0215] NKT cells were cultured on six well plates, and were washed
and lysed in lysis buffer. Spleens were crushed through a stainless
mesh (size 60, Sigma Chemical Co., St Louis Mo.). Cell suspension
was placed in a 50 ml tube for 3 minutes and washed twice in cold
PBS (1,250 rpm for 10 minutes), and debris was removed. Cells were
re-suspended in PBS, and placed through a nylon mesh presoaked in
PBS, and unbound cells were collected. Cells were washed twice in
45 ml PBS (1,250 rpm at room temperature). For splenocyte
isolation, 20 ml of histopaque 1077 (Sigma Diagnostics, St. Louis,
Mo.) was slowly placed underneath the cells suspended in 7 ml of
PBS, in a 50-ml tube. The tube was centrifuged at 1,640 rpm for 15
minutes at room temperature. Cells at the interface were collected,
diluted in a 50-ml tube, and washed twice with ice-cold PBS (1,250
rpm for 10 minutes). The viability by trypan blue staining was more
than 95%. Cell separation was performed using Magnetic Cell Sorting
(MACS). For NKT cells, both anti CD3 and anti-NK1.1 were used
(Miltenyl Biotec, Bergisch Gladbach, Germany).
[0216] Cell lysate was transferred to micro centrifuge tubes and
clarified by centrifugation. The supernatant was collected and the
protein content was determined by a BCA protein assay kit For
Western blotting analysis, equal amounts of protein were separated
by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis
[8%] and were transferred onto a nitrocellulose membrane. The
membrane was immuno-blotted with goat anti-leptin receptor
antibodies (Santa Cruz, USA).
Mice Groups
[0217] All mice were purchased from Harlan laboratories. All
animals were housed at controlled temperature at the Animal Core of
the Hadassah-Hebrew University Medical School. Mice were kept on
regular 12 hour light-dark cycles, fed standard mice chow and have
access to tap water from bottles. Mice were weighed and food intake
was recorded every two days. Mice were sacrificed on day 30 of the
experiment by cervical dislocation, under isoflurane
anesthesia.
Induction of HCC
[0218] 1.times.10.sup.8 HCC cells (of HEPA 1-6 origin) were
injected intraperitoneally into wildtype c57bl and leptin-deficient
ob/ob mice in order to determine the effect of leptin on HCC growth
in these mice. Monitoring of tumor growth was performed weekly by
mouse weighing and determination of tumor diameter by calipers. Any
mouse that featured a loss of over 20% in body weight, exhibited
signs of distress, or had an estimated tumor size of more than 15%
of animal weight, was sacrificed.
Leptin Administration
[0219] Recombinant mouse leptin was purchased from R&D Co, and
dissolved according to manufacturer's instructions. Leptin was
administered in two daily intraperitoneal injections, at a dose of
0.5 .mu.g/gram body weight per injection, as illustrated in Table 3
(see Example 2).
Pathological Examination
[0220] Hematoxylin/eosin staining of paraffin-embedded liver and
tumor sections was performed. Sections were examined by two
experienced pathologists, blinded to the criteria of the
experiment.
Splenic and Hepatic Lymphocyte Isolation
[0221] Splenocytes were isolated and red blood cells removed as
previously described [Shibolet, O. et al., J Leukoc Biol.
75(1):76-86 (2003)]. Intrahepatic lymphocytes were isolated from
all groups of mice at the end of the study. The inferior vena cava
was cut above the diaphragm and the liver was flushed with 5 ml of
cold PBS until it became pale. The connective tissue and gall
bladder were removed, and livers were placed in a 10-ml dish in
cold sterile PBS. Livers and spleens were crushed through a
stainless mesh (size 60, Sigma Chemical Co., St. Louis Mo.). Cell
suspension was placed in a 50-ml tube for 3 minutes and washed
twice in cold PBS (1,250.times.rpm for 10 minutes), and debris was
removed. Cells were re-suspended in PBS, cell suspension was placed
through a nylon mesh presoaked in PBS, and unbound cells were
collected. Cells were washed twice in 45 ml PBS (1,250.times.rpm in
room temperature). Liver and spleen lymphocyte isolation was
performed as described above for NK T and dendritic cell
isolation.
Flow Cytometry Analysis for Determination of Lymphocyte
Subpopulations
[0222] Immediately following lymphocyte isolation, triplicates of
2-5.times.10.sup.4 cells/500 .mu.l PBS were put into Falcon 2052
tubes incubated with 4 ml of 1% BSA for 10 minutes, and centrifuged
at 1400 rpm for 5 minutes. Cells were resuspended in 10 .mu.l FCS
with 1:20 FITC-anti mouse NK1.1 antibody (NKR-P1C, Pharmingen,
USA), and mixed every 10 minutes for 30 minutes. Cells were washed
twice in 1% BSA, and kept at 4.degree. C. until reading. For the
control group, only 541 of 1% BSA were added. Analytical cell
sorting was performed on 1.times.10.sup.4 cells from each group
with a fluorescence-activated cell sorter (FACSTAR plus, Becton
Dickinson). Only live cells were counted, and background
fluorescence from non-antibody-treated lymphocytes was deducted
from the levels obtained. Gates were set on forward- and
side-scatters to exclude dead cells and red blood cells. The data
was analyzed with Consort 30 two-color contour plot program (Becton
Dickinson, Oxnard, Calif.), or the CELLQuest program.
In Vitro Lymphocyte Incubation
[0223] 1.times.10.sup.5 splenic lymphocytes from each mouse were
cultured in 96-well plates in the presence of concanavalin A (used
here as a T lymphocyte activator), for 24 hours. Subsequently,
plates were centrifuged and the supernatant fluid removed.
Determination of supernatant levels of IFN-g, IL10, IL12 was
performed using `sandwich ELISA` (described above).
HCC in T Cell Deficient Mice
[0224] The above experiments were repeated in T cell deficient nude
mice. 1.times.10.sup.7 HEP-3B HCC cells were injected
subcutaneously, with or without the addition of leptin, as outlined
in Table 1 below. Follow-up parameters were identical to the ones
described above. TABLE-US-00001 TABLE 1 In vivo nude mice
experimental groups (n = 10) Group A Ten-week-old male nude mice +
HCC + 1 .mu.g/g/day leptin Group B Ten-week-old male nude mice +
HCC Group C Ten-week-old male nude mice + 1 .mu.g/g/day leptin
Group D Ten-week-old male C57BL/6 mice
Example 1
In-Vitro Addition of Increasing Doses of Leptin Results in Enhanced
APC-Dependent NKT Lymphocyte Proliferation
[0225] In order to assert the immunomodulatory effects of leptin on
regulatory cell (NKT and dendritic cell) proliferation and cytokine
secretion profile, the inventors have performed a series of
in-vitro experiments assessing the effect of leptin on NKT
lymphocyte proliferation, particularly in the presence of HCC
related antigens. NKT cells were harvested from wildtype c57bl mice
using double beading techniques (anti-CD3+ anti-NK1.1. &
anti-CD11a, for NKT and dendritic cells, respectively), as
described in Experimental Procedures. Triplicates of
1.times.10.sup.5 NKT cells were either incubated alone, or with the
addition of 1.times.10.sup.4 dendritic cells (DC). A crude lisate
of HEPA 1-6 HCC cells (made out from 5.times.10.sup.6 cells), and
increasing doses of leptin were added to each plate, as indicated
in Table 2, which lists all experimental groups. The same
experiment was later repeated using a human HEP-3B HCC lysate, in
order to determine whether the same response occurs in the presence
of human HCC antigens.
[0226] Plates were incubated for one day, and NKT cell
proliferation was determined using thymidine uptake techniques. As
shown by FIG. 1, higher doses of leptin resulted in greater NKT
cell proliferation, in particularly in plates where NKT cells were
incubated together with DC's (270 CPM, P<0.05). These results
indicate that incubation of NKT cells with escalating doses of
leptin, in the presence of tumor related antigens, results in
increased NKT proliferation, when these cells are incubated
together with dendritic cells. This suggests that leptin features a
direct, dose-dependent, pro-proliferative influence on NKT cells,
through activation of DC's. TABLE-US-00002 TABLE 2 Experimental
groups (triplicates) Group Cells Leptin HCC antigens Group A NKT
cell No leptin 5 .times. 10.sup.6 HEP 1-6 cell lysate Group B NKT
cell + DC No leptin 5 .times. 10.sup.6 HEP 1-6 cell lysate Group C
NKT cell 0.5 ng/ml leptin 5 .times. 10.sup.6 HEP 1-6 cell lysate
Group D NKT cell + DC 0.5 ng/ml leptin 5 .times. 10.sup.6 HEP 1-6
cell lysate Group E NKT cell 5 ng/ml leptin 5 .times. 10.sup.6 HEP
1-6 cell lysate Group F NKT cell + DC 5 ng/ml leptin 5 .times.
10.sup.6 HEP 1-6 cell lysate Group G NKT cell 50 ng/ml leptin 5
.times. 10.sup.6 HEP 1-6 cell lysate Group H NKT cell + DC 50 ng/ml
leptin 5 .times. 10.sup.6 HEP 1-6 cell lysate
Example 2
Leptin Leads to Induction of HCC in T Cell Deficient Nude Mice
which Results in a Substantial Increment in Tumor Growth
[0227] In vitro and in vivo experiments were next performed in
order to determine the presence of leptin receptors on HCC cells
grown in cell culture. Since it was previously found that
enhancement of tumor cell growth by leptin occurs through
activation of the JAK/STAT pathway, the inventors further examined
the effect of leptin addition on expression of STAT and STAT
intracellular proteins. It should be noted that in vitro, leptin
receptor mRNA expression and leptin-induced expression of signal
transducer and activators (STAT) 1-6, suppressor of cytokine
signaling (SOCS) 1-4, and cytokine-inducible S--H protein (CIS)
were determined in human HEPA-3B HCC cells. Subsequently, HCC was
induced in leptin-deficient ob/ob mice [Schwartz, J. et al., Clin.
Invest. 98(5):1101-6 (1996)] and their lean littermates, with or
without the addition of leptin, as illustrated in Table 3, and the
effect of leptin and leptin deficiency on HCC growth was
determined. To analyze the direct and immune-mediated effects of
leptin, HCC was induced as control in T cell deficient nude mice,
with or without the addition of exogenous leptin.
[0228] As shown by FIG. 2, Induction of HEP 3B human HCC in immune
deficient nude mice resulted in a significant decrease in tumor
growth (FIG. 2B) in the presence of leptin (although these tumors
showed a large necrotic center), in comparison to mice that were
not treated with leptin (FIG. 2A). It should be noted that changes
were notable after only five weeks of follow-up. TABLE-US-00003
TABLE 3 In vivo ob/ob experimental groups (n = 10) Group A
Ten-week-old male ob/ob mice + PBS Group B Ten-week-old male
C57BL/6 mice + PBS Group C Ten-week-old male ob/ob mice + 1
.mu.g/g/day leptin Group D Ten-week-old male C57BL/6 mice + 1
.mu.g/g/day leptin Group E Ten-week-old male ob/ob mice + HCC + PBS
Group F Ten-week-old male C57BL/6 mice + HCC + PBS Group G
Ten-week-old male ob/ob mice + HCC + 1 .mu.g/g/day leptin Group H
Ten-week-old male C57BL/6 mice + HCC + 1 .mu.g/g/day leptin
[0229] A comparative experiment, in which tumors of mice treated
with leptin and mice which were not treated with leptin, is
demonstrated by FIG. 3. As shown by the figure, tumors of mice that
were treated with leptin (top row) were significantly smaller then
tumors taken from mice which were not treated with leptin (bottom
row).
[0230] However, histological evaluation of excised tumors of both
groups (FIG. 3), clearly demonstrated that mice treated with leptin
uniformly developed an intense inflammatory response in tumor
interphase areas (FIG. 3B), whereas tumors of mice which were not
treated with leptin, showed no inflammatory response.
[0231] These results clearly demonstrate the feasibility of the use
of leptin for decreasing tumor size, and indicate that reduction of
tumor size by leptin may be a result of an immuno-modulatory effect
of leptin on induction of a pro-inflammatory response.
Example 3
Leptin Induces a Potent Pro-Inflammatory Immune Response in the
Concanavalin A Hepatic Damage Model
[0232] To assess the immunomodulatory role of leptin on NKT cell
dependent hepatic disease, the effect of leptin was assessed in the
concanavalin A-induced hepatitis model [Watanabe, Y. et al.,
Hepatology 24(3):702-10 (1996)]. Wildtype c57bl/6 mice were divided
into 4 groups, as shown in Table 4. Group A and C mice were
administered with two daily intraperitoneal injections of 0.5 mg/g
body weight leptin for one week. On day eight, mice of groups A and
B were intravenously administered with 20 mg/g concanavalin A
(conA). Eight hours later all mice were sacrificed.
[0233] Leptin administration resulted in significantly exacerbated
concanavalin-induced hepatitis. Group A mice featured significantly
elevated serum ALT activity (4578.+-.2226 u/l, FIG. 5) in
comparison to group B mice (2035.+-.446 u/l, P<0.05). Hepatic
histology from group A mice demonstrated significantly increased
hepatic necrosis and inflammation as compared to group B mice (FIG.
6). The administration of leptin without the induction of
concanavalin A hepatitis did not in itself result in elevated ALT
(alanine amino transferase) levels (114.+-.101 ul) or hepatic
necrosis (FIGS. 5 and 6, respectively). TABLE-US-00004 TABLE 4
Preliminary experiment B groups (N = 10) Group Leptin Concanavalin
A Group A + + Group B - + Group C + - Group D - -
* * * * *